<?xml version="1.0" encoding="UTF-8"?>

<!--XBRL Document Created with the Workiva Platform-->
<!--Copyright 2024 Workiva-->
<!--r:535720cf-72ff-42d5-83e7-f7e6eb79b142,g:cb25fe10-a8f7-4c74-83c8-5d456b638db7-->
<link:linkbase xmlns:link="http://www.xbrl.org/2003/linkbase" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.xbrl.org/2003/linkbase http://www.xbrl.org/2003/xbrl-linkbase-2003-12-31.xsd">
  <link:roleRef roleURI="http://cassinfo.com/role/CONSOLIDATEDBALANCESHEETS" xlink:type="simple" xlink:href="cass-20240930.xsd#CONSOLIDATEDBALANCESHEETS"/>
  <link:calculationLink xlink:role="http://cassinfo.com/role/CONSOLIDATEDBALANCESHEETS" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CashCashEquivalentsAndShortTermInvestments_246bbaa9-8088-46fa-8bae-413698508fdc" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CashCashEquivalentsAndShortTermInvestments"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CashAndDueFromBanks_4a879360-d701-479e-a321-2aed6877dfae" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CashAndDueFromBanks"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_CashCashEquivalentsAndShortTermInvestments_246bbaa9-8088-46fa-8bae-413698508fdc" xlink:to="loc_us-gaap_CashAndDueFromBanks_4a879360-d701-479e-a321-2aed6877dfae" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShortTermInvestments_ce0df66d-047d-4088-bb72-0b24905b1ba1" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ShortTermInvestments"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_CashCashEquivalentsAndShortTermInvestments_246bbaa9-8088-46fa-8bae-413698508fdc" xlink:to="loc_us-gaap_ShortTermInvestments_ce0df66d-047d-4088-bb72-0b24905b1ba1" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableExcludingAccruedInterestAfterAllowanceForCreditLoss_a4a1a608-09d4-46f5-bfdc-109b82d0ad12" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_FinancingReceivableExcludingAccruedInterestAfterAllowanceForCreditLoss"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableExcludingAccruedInterestBeforeAllowanceForCreditLoss_df5eceda-fd43-4cb6-a244-b02b2aaa07c6" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_FinancingReceivableExcludingAccruedInterestBeforeAllowanceForCreditLoss"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_FinancingReceivableExcludingAccruedInterestAfterAllowanceForCreditLoss_a4a1a608-09d4-46f5-bfdc-109b82d0ad12" xlink:to="loc_us-gaap_FinancingReceivableExcludingAccruedInterestBeforeAllowanceForCreditLoss_df5eceda-fd43-4cb6-a244-b02b2aaa07c6" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableAllowanceForCreditLossExcludingAccruedInterest_bd14e101-0d95-4f69-878f-2db8920dbfae" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_FinancingReceivableAllowanceForCreditLossExcludingAccruedInterest"/>
    <link:calculationArc order="2" weight="-1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_FinancingReceivableExcludingAccruedInterestAfterAllowanceForCreditLoss_a4a1a608-09d4-46f5-bfdc-109b82d0ad12" xlink:to="loc_us-gaap_FinancingReceivableAllowanceForCreditLossExcludingAccruedInterest_bd14e101-0d95-4f69-878f-2db8920dbfae" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquity_d460bca8-dfe3-4843-a16f-e57d564d237d" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StockholdersEquity"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PreferredStockValue_a8cca29b-8f16-4083-8faf-1cecb045dbfc" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PreferredStockValue"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_StockholdersEquity_d460bca8-dfe3-4843-a16f-e57d564d237d" xlink:to="loc_us-gaap_PreferredStockValue_a8cca29b-8f16-4083-8faf-1cecb045dbfc" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockValueOutstanding_3d135b51-c6ca-49a6-8679-6e030bdc46a2" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CommonStockValueOutstanding"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_StockholdersEquity_d460bca8-dfe3-4843-a16f-e57d564d237d" xlink:to="loc_us-gaap_CommonStockValueOutstanding_3d135b51-c6ca-49a6-8679-6e030bdc46a2" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AdditionalPaidInCapitalCommonStock_b400bd9b-967a-492a-a0ef-cd152b4e892c" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_AdditionalPaidInCapitalCommonStock"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_StockholdersEquity_d460bca8-dfe3-4843-a16f-e57d564d237d" xlink:to="loc_us-gaap_AdditionalPaidInCapitalCommonStock_b400bd9b-967a-492a-a0ef-cd152b4e892c" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetainedEarningsAccumulatedDeficit_7dcf8211-0da9-4633-bc7f-91e3d1c2036c" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_RetainedEarningsAccumulatedDeficit"/>
    <link:calculationArc order="4" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_StockholdersEquity_d460bca8-dfe3-4843-a16f-e57d564d237d" xlink:to="loc_us-gaap_RetainedEarningsAccumulatedDeficit_7dcf8211-0da9-4633-bc7f-91e3d1c2036c" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TreasuryStockCommonValue_ba9ee64b-f012-42b0-b036-63d9d997eacc" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_TreasuryStockCommonValue"/>
    <link:calculationArc order="5" weight="-1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_StockholdersEquity_d460bca8-dfe3-4843-a16f-e57d564d237d" xlink:to="loc_us-gaap_TreasuryStockCommonValue_ba9ee64b-f012-42b0-b036-63d9d997eacc" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax_13208b17-42db-42ac-a7af-fb1e8680fd12" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax"/>
    <link:calculationArc order="6" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_StockholdersEquity_d460bca8-dfe3-4843-a16f-e57d564d237d" xlink:to="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax_13208b17-42db-42ac-a7af-fb1e8680fd12" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Assets_3678eb39-11c6-4d75-84f3-a9f6ce3433f8" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_Assets"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CashCashEquivalentsAndShortTermInvestments_4ccc329d-4864-4658-af28-7f70f5022a97" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CashCashEquivalentsAndShortTermInvestments"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_Assets_3678eb39-11c6-4d75-84f3-a9f6ce3433f8" xlink:to="loc_us-gaap_CashCashEquivalentsAndShortTermInvestments_4ccc329d-4864-4658-af28-7f70f5022a97" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableExcludingAccruedInterestAfterAllowanceForCreditLoss_e5dfccde-b18e-4dba-9b26-6c9eb4183fb8" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_FinancingReceivableExcludingAccruedInterestAfterAllowanceForCreditLoss"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_Assets_3678eb39-11c6-4d75-84f3-a9f6ce3433f8" xlink:to="loc_us-gaap_FinancingReceivableExcludingAccruedInterestAfterAllowanceForCreditLoss_e5dfccde-b18e-4dba-9b26-6c9eb4183fb8" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentNet_28252193-2b2d-47e3-a1b5-b3e31934f0a6" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PropertyPlantAndEquipmentNet"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_Assets_3678eb39-11c6-4d75-84f3-a9f6ce3433f8" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentNet_28252193-2b2d-47e3-a1b5-b3e31934f0a6" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtSecuritiesAvailableForSaleExcludingAccruedInterest_210554e0-21af-4221-9f21-9c6f1d79c95d" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DebtSecuritiesAvailableForSaleExcludingAccruedInterest"/>
    <link:calculationArc order="4" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_Assets_3678eb39-11c6-4d75-84f3-a9f6ce3433f8" xlink:to="loc_us-gaap_DebtSecuritiesAvailableForSaleExcludingAccruedInterest_210554e0-21af-4221-9f21-9c6f1d79c95d" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BankOwnedLifeInsurance_88e95339-d270-42b9-86f9-092b3fa48959" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_BankOwnedLifeInsurance"/>
    <link:calculationArc order="5" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_Assets_3678eb39-11c6-4d75-84f3-a9f6ce3433f8" xlink:to="loc_us-gaap_BankOwnedLifeInsurance_88e95339-d270-42b9-86f9-092b3fa48959" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_cass_PaymentsInAdvanceOfFunding_61270405-479f-4e49-a1d6-69146d055ebb" xlink:href="cass-20240930.xsd#cass_PaymentsInAdvanceOfFunding"/>
    <link:calculationArc order="6" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_Assets_3678eb39-11c6-4d75-84f3-a9f6ce3433f8" xlink:to="loc_cass_PaymentsInAdvanceOfFunding_61270405-479f-4e49-a1d6-69146d055ebb" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Goodwill_ac73232c-2dbd-4569-a929-9f2c4133684f" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_Goodwill"/>
    <link:calculationArc order="7" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_Assets_3678eb39-11c6-4d75-84f3-a9f6ce3433f8" xlink:to="loc_us-gaap_Goodwill_ac73232c-2dbd-4569-a929-9f2c4133684f" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IntangibleAssetsNetExcludingGoodwill_cd657817-dd78-400b-94e1-519f044f12e7" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_IntangibleAssetsNetExcludingGoodwill"/>
    <link:calculationArc order="8" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_Assets_3678eb39-11c6-4d75-84f3-a9f6ce3433f8" xlink:to="loc_us-gaap_IntangibleAssetsNetExcludingGoodwill_cd657817-dd78-400b-94e1-519f044f12e7" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ReceivablesFromCustomers_fbd2c434-c907-4fa9-9232-52ce329f4b32" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ReceivablesFromCustomers"/>
    <link:calculationArc order="9" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_Assets_3678eb39-11c6-4d75-84f3-a9f6ce3433f8" xlink:to="loc_us-gaap_ReceivablesFromCustomers_fbd2c434-c907-4fa9-9232-52ce329f4b32" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherAssets_c488b1d4-8514-488d-a924-1b3015d8ac85" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_OtherAssets"/>
    <link:calculationArc order="10" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_Assets_3678eb39-11c6-4d75-84f3-a9f6ce3433f8" xlink:to="loc_us-gaap_OtherAssets_c488b1d4-8514-488d-a924-1b3015d8ac85" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LiabilitiesAndStockholdersEquity_8a116b4a-e7e5-477a-ba5b-2915bc6c4c23" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LiabilitiesAndStockholdersEquity"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Liabilities_7249d8fd-16bf-42cd-8559-bf2d97a5af30" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_Liabilities"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquity_8a116b4a-e7e5-477a-ba5b-2915bc6c4c23" xlink:to="loc_us-gaap_Liabilities_7249d8fd-16bf-42cd-8559-bf2d97a5af30" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquity_ac2b61fa-f1ed-49dd-94ed-05c11151ddce" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StockholdersEquity"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquity_8a116b4a-e7e5-477a-ba5b-2915bc6c4c23" xlink:to="loc_us-gaap_StockholdersEquity_ac2b61fa-f1ed-49dd-94ed-05c11151ddce" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Liabilities_d26324f8-32a3-493a-9954-a2d8b552e844" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_Liabilities"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Deposits_ce613ae0-ddec-4f54-9482-4308482e6bad" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_Deposits"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_Liabilities_d26324f8-32a3-493a-9954-a2d8b552e844" xlink:to="loc_us-gaap_Deposits_ce613ae0-ddec-4f54-9482-4308482e6bad" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_cass_AccountsAndDraftsPayable_03836992-3a14-4d02-8e52-0ac54e4a5ec1" xlink:href="cass-20240930.xsd#cass_AccountsAndDraftsPayable"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_Liabilities_d26324f8-32a3-493a-9954-a2d8b552e844" xlink:to="loc_cass_AccountsAndDraftsPayable_03836992-3a14-4d02-8e52-0ac54e4a5ec1" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherLiabilities_4a4f0a8d-97f8-423a-92d8-929d386a06ce" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_OtherLiabilities"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_Liabilities_d26324f8-32a3-493a-9954-a2d8b552e844" xlink:to="loc_us-gaap_OtherLiabilities_4a4f0a8d-97f8-423a-92d8-929d386a06ce" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Deposits_82f2e79d-289b-493b-a07b-ce7f7c317ab0" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_Deposits"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NoninterestBearingDepositLiabilities_b4a4646a-61af-43cf-bf11-d8b4bead3496" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_NoninterestBearingDepositLiabilities"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_Deposits_82f2e79d-289b-493b-a07b-ce7f7c317ab0" xlink:to="loc_us-gaap_NoninterestBearingDepositLiabilities_b4a4646a-61af-43cf-bf11-d8b4bead3496" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestBearingDepositLiabilities_8f220000-8e3f-45d5-89ca-fa58e8512d0b" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_InterestBearingDepositLiabilities"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_Deposits_82f2e79d-289b-493b-a07b-ce7f7c317ab0" xlink:to="loc_us-gaap_InterestBearingDepositLiabilities_8f220000-8e3f-45d5-89ca-fa58e8512d0b" xlink:type="arc"/>
  </link:calculationLink>
  <link:roleRef roleURI="http://cassinfo.com/role/CONSOLIDATEDSTATEMENTSOFINCOME" xlink:type="simple" xlink:href="cass-20240930.xsd#CONSOLIDATEDSTATEMENTSOFINCOME"/>
  <link:calculationLink xlink:role="http://cassinfo.com/role/CONSOLIDATEDSTATEMENTSOFINCOME" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestAndDividendIncomeOperating_bc641c8f-05ad-4f3c-884f-46ef3307ae43" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_InterestAndDividendIncomeOperating"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestAndFeeIncomeLoansAndLeases_4e0b6233-c468-45ba-910d-5d6d0bc7f217" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_InterestAndFeeIncomeLoansAndLeases"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_InterestAndDividendIncomeOperating_bc641c8f-05ad-4f3c-884f-46ef3307ae43" xlink:to="loc_us-gaap_InterestAndFeeIncomeLoansAndLeases_4e0b6233-c468-45ba-910d-5d6d0bc7f217" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestIncomeSecuritiesTaxable_8013204c-b2ce-4a97-933e-e792b19b3955" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_InterestIncomeSecuritiesTaxable"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_InterestAndDividendIncomeOperating_bc641c8f-05ad-4f3c-884f-46ef3307ae43" xlink:to="loc_us-gaap_InterestIncomeSecuritiesTaxable_8013204c-b2ce-4a97-933e-e792b19b3955" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestIncomeSecuritiesTaxExempt_e21cb580-7963-4fcf-a5ab-26f57c6d686b" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_InterestIncomeSecuritiesTaxExempt"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_InterestAndDividendIncomeOperating_bc641c8f-05ad-4f3c-884f-46ef3307ae43" xlink:to="loc_us-gaap_InterestIncomeSecuritiesTaxExempt_e21cb580-7963-4fcf-a5ab-26f57c6d686b" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_cass_InterestOnFederalFundsSoldAndOtherShortTermInvestments_c357013c-fe41-4e0f-9dab-c2612167efae" xlink:href="cass-20240930.xsd#cass_InterestOnFederalFundsSoldAndOtherShortTermInvestments"/>
    <link:calculationArc order="4" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_InterestAndDividendIncomeOperating_bc641c8f-05ad-4f3c-884f-46ef3307ae43" xlink:to="loc_cass_InterestOnFederalFundsSoldAndOtherShortTermInvestments_c357013c-fe41-4e0f-9dab-c2612167efae" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestIncomeExpenseAfterProvisionForLoanLoss_1a7c5b2f-6f6a-42bc-8034-7291f5a189aa" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_InterestIncomeExpenseAfterProvisionForLoanLoss"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestIncomeExpenseNet_cf3d1eb2-5e2e-4535-95c6-6fb247b699e2" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_InterestIncomeExpenseNet"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_InterestIncomeExpenseAfterProvisionForLoanLoss_1a7c5b2f-6f6a-42bc-8034-7291f5a189aa" xlink:to="loc_us-gaap_InterestIncomeExpenseNet_cf3d1eb2-5e2e-4535-95c6-6fb247b699e2" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProvisionForLoanLossesExpensed_af78f7a7-0395-4a2f-8676-93ecd82c2d46" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ProvisionForLoanLossesExpensed"/>
    <link:calculationArc order="2" weight="-1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_InterestIncomeExpenseAfterProvisionForLoanLoss_1a7c5b2f-6f6a-42bc-8034-7291f5a189aa" xlink:to="loc_us-gaap_ProvisionForLoanLossesExpensed_af78f7a7-0395-4a2f-8676-93ecd82c2d46" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetIncomeLoss_d1ff5552-9d42-426e-8ecc-59b666b92ee4" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_NetIncomeLoss"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest_0b1961c1-25cb-499a-a886-d687fe4dd69c" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetIncomeLoss_d1ff5552-9d42-426e-8ecc-59b666b92ee4" xlink:to="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest_0b1961c1-25cb-499a-a886-d687fe4dd69c" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeTaxExpenseBenefit_bce2efc4-7496-40f2-8047-aaa473c3db9b" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_IncomeTaxExpenseBenefit"/>
    <link:calculationArc order="2" weight="-1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetIncomeLoss_d1ff5552-9d42-426e-8ecc-59b666b92ee4" xlink:to="loc_us-gaap_IncomeTaxExpenseBenefit_bce2efc4-7496-40f2-8047-aaa473c3db9b" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Revenues_5ba56966-8702-4fd9-b4d8-2e7f401bf6cc" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_Revenues"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NoninterestIncome_a5b1cde2-5892-4e73-a805-0613bd9c1c05" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_NoninterestIncome"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_Revenues_5ba56966-8702-4fd9-b4d8-2e7f401bf6cc" xlink:to="loc_us-gaap_NoninterestIncome_a5b1cde2-5892-4e73-a805-0613bd9c1c05" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestIncomeExpenseAfterProvisionForLoanLoss_aebff68a-a544-40f4-98df-df147d117edb" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_InterestIncomeExpenseAfterProvisionForLoanLoss"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_Revenues_5ba56966-8702-4fd9-b4d8-2e7f401bf6cc" xlink:to="loc_us-gaap_InterestIncomeExpenseAfterProvisionForLoanLoss_aebff68a-a544-40f4-98df-df147d117edb" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest_6095b81b-fab3-4342-aca2-f2ce05356e62" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Revenues_c5584e17-1957-4d4d-a9a9-6ee66576c7e8" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_Revenues"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest_6095b81b-fab3-4342-aca2-f2ce05356e62" xlink:to="loc_us-gaap_Revenues_c5584e17-1957-4d4d-a9a9-6ee66576c7e8" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NoninterestExpense_40d1d4a0-0a92-474b-b4f0-f66aa189c836" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_NoninterestExpense"/>
    <link:calculationArc order="2" weight="-1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest_6095b81b-fab3-4342-aca2-f2ce05356e62" xlink:to="loc_us-gaap_NoninterestExpense_40d1d4a0-0a92-474b-b4f0-f66aa189c836" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestIncomeExpenseNet_ea34ac37-b0dd-4664-a33d-26bef63c8492" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_InterestIncomeExpenseNet"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestExpense_01eb84b9-b7df-43be-a8ea-2aa260a7a698" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_InterestExpense"/>
    <link:calculationArc order="1" weight="-1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_InterestIncomeExpenseNet_ea34ac37-b0dd-4664-a33d-26bef63c8492" xlink:to="loc_us-gaap_InterestExpense_01eb84b9-b7df-43be-a8ea-2aa260a7a698" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestAndDividendIncomeOperating_a4cd25bf-d6bd-4544-9699-012e3fa26e6c" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_InterestAndDividendIncomeOperating"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_InterestIncomeExpenseNet_ea34ac37-b0dd-4664-a33d-26bef63c8492" xlink:to="loc_us-gaap_InterestAndDividendIncomeOperating_a4cd25bf-d6bd-4544-9699-012e3fa26e6c" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NoninterestExpense_bb54f0cc-409b-4a42-9dc2-73228c61dc0a" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_NoninterestExpense"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LaborAndRelatedExpense_29a9053c-f77d-45be-8b31-1eace0baa85c" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LaborAndRelatedExpense"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NoninterestExpense_bb54f0cc-409b-4a42-9dc2-73228c61dc0a" xlink:to="loc_us-gaap_LaborAndRelatedExpense_29a9053c-f77d-45be-8b31-1eace0baa85c" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OccupancyNet_a6b9301a-267a-4586-91ae-b927e727e065" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_OccupancyNet"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NoninterestExpense_bb54f0cc-409b-4a42-9dc2-73228c61dc0a" xlink:to="loc_us-gaap_OccupancyNet_a6b9301a-267a-4586-91ae-b927e727e065" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquipmentExpense_1d7f3063-2068-4a21-814b-5dd8e6330424" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_EquipmentExpense"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NoninterestExpense_bb54f0cc-409b-4a42-9dc2-73228c61dc0a" xlink:to="loc_us-gaap_EquipmentExpense_1d7f3063-2068-4a21-814b-5dd8e6330424" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AmortizationOfIntangibleAssets_0cb161df-fdf0-49cb-8c30-e0cf68d99b63" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_AmortizationOfIntangibleAssets"/>
    <link:calculationArc order="4" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NoninterestExpense_bb54f0cc-409b-4a42-9dc2-73228c61dc0a" xlink:to="loc_us-gaap_AmortizationOfIntangibleAssets_0cb161df-fdf0-49cb-8c30-e0cf68d99b63" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherNoninterestExpense_e2f7bea1-b4fe-4005-9306-774e72dd206b" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_OtherNoninterestExpense"/>
    <link:calculationArc order="5" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NoninterestExpense_bb54f0cc-409b-4a42-9dc2-73228c61dc0a" xlink:to="loc_us-gaap_OtherNoninterestExpense_e2f7bea1-b4fe-4005-9306-774e72dd206b" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_cass_BadDebtExpense_974768ad-2c96-4807-922a-c220ee4a556c" xlink:href="cass-20240930.xsd#cass_BadDebtExpense"/>
    <link:calculationArc order="6" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NoninterestExpense_bb54f0cc-409b-4a42-9dc2-73228c61dc0a" xlink:to="loc_cass_BadDebtExpense_974768ad-2c96-4807-922a-c220ee4a556c" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NoninterestIncome_001931b8-02fc-4ece-a774-c9258381c8d7" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_NoninterestIncome"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_c4fde4a2-1ccf-4f04-98f8-ee98bd1280bb" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NoninterestIncome_001931b8-02fc-4ece-a774-c9258381c8d7" xlink:to="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_c4fde4a2-1ccf-4f04-98f8-ee98bd1280bb" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueNotFromContractWithCustomerOther_a04e9344-61cc-4c5e-8c2b-dfe800448654" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_RevenueNotFromContractWithCustomerOther"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NoninterestIncome_001931b8-02fc-4ece-a774-c9258381c8d7" xlink:to="loc_us-gaap_RevenueNotFromContractWithCustomerOther_a04e9344-61cc-4c5e-8c2b-dfe800448654" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestExpense_c2ee74ae-aceb-4f96-8f1f-adedbbe4434f" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_InterestExpense"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestExpenseShortTermBorrowings_de821c33-a830-428a-bd0b-1846f5960b03" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_InterestExpenseShortTermBorrowings"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_InterestExpense_c2ee74ae-aceb-4f96-8f1f-adedbbe4434f" xlink:to="loc_us-gaap_InterestExpenseShortTermBorrowings_de821c33-a830-428a-bd0b-1846f5960b03" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestExpenseDeposits_57c23508-440a-4f49-ac39-bea9830dcb04" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_InterestExpenseDeposits"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_InterestExpense_c2ee74ae-aceb-4f96-8f1f-adedbbe4434f" xlink:to="loc_us-gaap_InterestExpenseDeposits_57c23508-440a-4f49-ac39-bea9830dcb04" xlink:type="arc"/>
  </link:calculationLink>
  <link:roleRef roleURI="http://cassinfo.com/role/CONSOLIDATEDSTATEMENTSOFCOMPREHENSIVEINCOME" xlink:type="simple" xlink:href="cass-20240930.xsd#CONSOLIDATEDSTATEMENTSOFCOMPREHENSIVEINCOME"/>
  <link:calculationLink xlink:role="http://cassinfo.com/role/CONSOLIDATEDSTATEMENTSOFCOMPREHENSIVEINCOME" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ComprehensiveIncomeNetOfTax_893a0414-3de3-4081-9d32-3d1830d9f6c6" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ComprehensiveIncomeNetOfTax"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetIncomeLoss_fa0d42f4-8e24-4dc1-9292-07ec274d8521" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_NetIncomeLoss"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_ComprehensiveIncomeNetOfTax_893a0414-3de3-4081-9d32-3d1830d9f6c6" xlink:to="loc_us-gaap_NetIncomeLoss_fa0d42f4-8e24-4dc1-9292-07ec274d8521" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodBeforeTax_9f94f68c-a5e2-4529-a1f3-3e6678b93a47" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodBeforeTax"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_ComprehensiveIncomeNetOfTax_893a0414-3de3-4081-9d32-3d1830d9f6c6" xlink:to="loc_us-gaap_OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodBeforeTax_9f94f68c-a5e2-4529-a1f3-3e6678b93a47" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodTax_5b3127bc-6583-4686-960c-df59fd694d12" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodTax"/>
    <link:calculationArc order="3" weight="-1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_ComprehensiveIncomeNetOfTax_893a0414-3de3-4081-9d32-3d1830d9f6c6" xlink:to="loc_us-gaap_OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodTax_5b3127bc-6583-4686-960c-df59fd694d12" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesBeforeTax_eeffbeef-45cf-4a77-b845-7c28d17fd213" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesBeforeTax"/>
    <link:calculationArc order="4" weight="-1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_ComprehensiveIncomeNetOfTax_893a0414-3de3-4081-9d32-3d1830d9f6c6" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesBeforeTax_eeffbeef-45cf-4a77-b845-7c28d17fd213" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesTax_a69a0785-3fd6-4d37-a75e-792055a4f51d" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesTax"/>
    <link:calculationArc order="5" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_ComprehensiveIncomeNetOfTax_893a0414-3de3-4081-9d32-3d1830d9f6c6" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesTax_a69a0785-3fd6-4d37-a75e-792055a4f51d" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossForeignCurrencyTransactionAndTranslationAdjustmentNetOfTax_e5a0a807-1a62-4bc4-9def-912441813ad2" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_OtherComprehensiveIncomeLossForeignCurrencyTransactionAndTranslationAdjustmentNetOfTax"/>
    <link:calculationArc order="6" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_ComprehensiveIncomeNetOfTax_893a0414-3de3-4081-9d32-3d1830d9f6c6" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossForeignCurrencyTransactionAndTranslationAdjustmentNetOfTax_e5a0a807-1a62-4bc4-9def-912441813ad2" xlink:type="arc"/>
  </link:calculationLink>
  <link:roleRef roleURI="http://cassinfo.com/role/CONSOLIDATEDSTATEMENTSOFCASHFLOWS" xlink:type="simple" xlink:href="cass-20240930.xsd#CONSOLIDATEDSTATEMENTSOFCASHFLOWS"/>
  <link:calculationLink xlink:role="http://cassinfo.com/role/CONSOLIDATEDSTATEMENTSOFCASHFLOWS" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetCashProvidedByUsedInFinancingActivities_2e767904-06af-4fc0-b82f-338cc887f2aa" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_NetCashProvidedByUsedInFinancingActivities"/>
    <link:loc xlink:type="locator" xlink:label="loc_cass_NetDecreaseInNoninterestBearingDemandDeposits_988ec69c-be6f-44e2-908c-e505503ef244" xlink:href="cass-20240930.xsd#cass_NetDecreaseInNoninterestBearingDemandDeposits"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivities_2e767904-06af-4fc0-b82f-338cc887f2aa" xlink:to="loc_cass_NetDecreaseInNoninterestBearingDemandDeposits_988ec69c-be6f-44e2-908c-e505503ef244" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_cass_IncreaseDecreaseInInterestBearingDemandAndSavingsDeposits_18f6c968-1e39-4efc-a72d-3f2025fc97c2" xlink:href="cass-20240930.xsd#cass_IncreaseDecreaseInInterestBearingDemandAndSavingsDeposits"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivities_2e767904-06af-4fc0-b82f-338cc887f2aa" xlink:to="loc_cass_IncreaseDecreaseInInterestBearingDemandAndSavingsDeposits_18f6c968-1e39-4efc-a72d-3f2025fc97c2" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncreaseDecreaseInTimeDeposits_de07ca1c-f0ac-407d-a090-225019233965" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_IncreaseDecreaseInTimeDeposits"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivities_2e767904-06af-4fc0-b82f-338cc887f2aa" xlink:to="loc_us-gaap_IncreaseDecreaseInTimeDeposits_de07ca1c-f0ac-407d-a090-225019233965" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_cass_NetIncreaseDecreaseInAccountsAndDraftsReceivableFromCustomers_93fd7789-b091-4ae8-a5c1-e0a178641c2b" xlink:href="cass-20240930.xsd#cass_NetIncreaseDecreaseInAccountsAndDraftsReceivableFromCustomers"/>
    <link:calculationArc order="4" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivities_2e767904-06af-4fc0-b82f-338cc887f2aa" xlink:to="loc_cass_NetIncreaseDecreaseInAccountsAndDraftsReceivableFromCustomers_93fd7789-b091-4ae8-a5c1-e0a178641c2b" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_cass_IncreaseInAccountsAndDraftsPayable_18a765cc-f7be-4e8e-b886-fe349354a9db" xlink:href="cass-20240930.xsd#cass_IncreaseInAccountsAndDraftsPayable"/>
    <link:calculationArc order="5" weight="-1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivities_2e767904-06af-4fc0-b82f-338cc887f2aa" xlink:to="loc_cass_IncreaseInAccountsAndDraftsPayable_18a765cc-f7be-4e8e-b886-fe349354a9db" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentsOfDividendsCommonStock_b929b78e-0c35-4850-b67b-c15e135d9a82" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PaymentsOfDividendsCommonStock"/>
    <link:calculationArc order="6" weight="-1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivities_2e767904-06af-4fc0-b82f-338cc887f2aa" xlink:to="loc_us-gaap_PaymentsOfDividendsCommonStock_b929b78e-0c35-4850-b67b-c15e135d9a82" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentsForRepurchaseOfCommonStock_d8c588df-df41-4a79-9cf5-b6196092a959" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PaymentsForRepurchaseOfCommonStock"/>
    <link:calculationArc order="7" weight="-1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivities_2e767904-06af-4fc0-b82f-338cc887f2aa" xlink:to="loc_us-gaap_PaymentsForRepurchaseOfCommonStock_d8c588df-df41-4a79-9cf5-b6196092a959" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProceedsFromPaymentsForOtherFinancingActivities_0ee33e76-8e6c-4d6d-b7c1-1e67150faf30" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ProceedsFromPaymentsForOtherFinancingActivities"/>
    <link:calculationArc order="8" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivities_2e767904-06af-4fc0-b82f-338cc887f2aa" xlink:to="loc_us-gaap_ProceedsFromPaymentsForOtherFinancingActivities_0ee33e76-8e6c-4d6d-b7c1-1e67150faf30" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_81563936-e750-41d1-b250-4baf130053a5" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_NetCashProvidedByUsedInOperatingActivities"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetIncomeLoss_81f3491e-5344-4102-938a-9d0defbceeec" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_NetIncomeLoss"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_81563936-e750-41d1-b250-4baf130053a5" xlink:to="loc_us-gaap_NetIncomeLoss_81f3491e-5344-4102-938a-9d0defbceeec" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AmortizationOfIntangibleAssets_90f173e0-a141-4451-9da8-ea5c94b1543b" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_AmortizationOfIntangibleAssets"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_81563936-e750-41d1-b250-4baf130053a5" xlink:to="loc_us-gaap_AmortizationOfIntangibleAssets_90f173e0-a141-4451-9da8-ea5c94b1543b" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccretionAmortizationOfDiscountsAndPremiumsInvestments_1cb27780-4c61-4fa4-a1aa-af689f7c4ac9" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_AccretionAmortizationOfDiscountsAndPremiumsInvestments"/>
    <link:calculationArc order="3" weight="-1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_81563936-e750-41d1-b250-4baf130053a5" xlink:to="loc_us-gaap_AccretionAmortizationOfDiscountsAndPremiumsInvestments_1cb27780-4c61-4fa4-a1aa-af689f7c4ac9" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Depreciation_e32565b5-3ccb-4c6b-8d1f-6d1ec9246477" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_Depreciation"/>
    <link:calculationArc order="4" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_81563936-e750-41d1-b250-4baf130053a5" xlink:to="loc_us-gaap_Depreciation_e32565b5-3ccb-4c6b-8d1f-6d1ec9246477" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtAndEquitySecuritiesGainLoss_7ab6135a-137b-42f2-a2d3-457011564a66" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DebtAndEquitySecuritiesGainLoss"/>
    <link:calculationArc order="5" weight="-1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_81563936-e750-41d1-b250-4baf130053a5" xlink:to="loc_us-gaap_DebtAndEquitySecuritiesGainLoss_7ab6135a-137b-42f2-a2d3-457011564a66" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProvisionForLoanLossesExpensed_56f61d2c-de74-466d-acb2-7a6d8a58f671" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ProvisionForLoanLossesExpensed"/>
    <link:calculationArc order="6" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_81563936-e750-41d1-b250-4baf130053a5" xlink:to="loc_us-gaap_ProvisionForLoanLossesExpensed_56f61d2c-de74-466d-acb2-7a6d8a58f671" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherOperatingActivitiesCashFlowStatement_bc14fc7e-ba97-4716-af8d-c15ec32a7ed8" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_OtherOperatingActivitiesCashFlowStatement"/>
    <link:calculationArc order="7" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_81563936-e750-41d1-b250-4baf130053a5" xlink:to="loc_us-gaap_OtherOperatingActivitiesCashFlowStatement_bc14fc7e-ba97-4716-af8d-c15ec32a7ed8" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncreaseDecreaseInPensionPlanObligations_4b580f85-6c1c-4a83-b498-42c2ac55dbb1" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_IncreaseDecreaseInPensionPlanObligations"/>
    <link:calculationArc order="8" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_81563936-e750-41d1-b250-4baf130053a5" xlink:to="loc_us-gaap_IncreaseDecreaseInPensionPlanObligations_4b580f85-6c1c-4a83-b498-42c2ac55dbb1" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncreaseDecreaseInAccruedIncomeTaxesPayable_bcbe7dbb-1fac-4e91-be51-bc23d3a1face" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_IncreaseDecreaseInAccruedIncomeTaxesPayable"/>
    <link:calculationArc order="9" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_81563936-e750-41d1-b250-4baf130053a5" xlink:to="loc_us-gaap_IncreaseDecreaseInAccruedIncomeTaxesPayable_bcbe7dbb-1fac-4e91-be51-bc23d3a1face" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncreaseDecreaseInAccountsReceivable_be3993f4-a3ba-4009-ac7e-5dab6b301f16" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_IncreaseDecreaseInAccountsReceivable"/>
    <link:calculationArc order="10" weight="-1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_81563936-e750-41d1-b250-4baf130053a5" xlink:to="loc_us-gaap_IncreaseDecreaseInAccountsReceivable_be3993f4-a3ba-4009-ac7e-5dab6b301f16" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensation_e4355784-bb0b-4529-b60e-e443612fb0fc" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ShareBasedCompensation"/>
    <link:calculationArc order="11" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_81563936-e750-41d1-b250-4baf130053a5" xlink:to="loc_us-gaap_ShareBasedCompensation_e4355784-bb0b-4529-b60e-e443612fb0fc" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetCashProvidedByUsedInInvestingActivities_b12a5e2b-e618-467f-a686-cffecc537899" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_NetCashProvidedByUsedInInvestingActivities"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProceedsFromMaturitiesPrepaymentsAndCallsOfAvailableForSaleSecurities_04aa83be-7b5f-461c-bd6b-d7ca72f91965" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ProceedsFromMaturitiesPrepaymentsAndCallsOfAvailableForSaleSecurities"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInInvestingActivities_b12a5e2b-e618-467f-a686-cffecc537899" xlink:to="loc_us-gaap_ProceedsFromMaturitiesPrepaymentsAndCallsOfAvailableForSaleSecurities_04aa83be-7b5f-461c-bd6b-d7ca72f91965" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProceedsFromSaleOfAvailableForSaleSecuritiesDebt_59cf4db7-e132-42a0-8363-ebaebae7803f" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ProceedsFromSaleOfAvailableForSaleSecuritiesDebt"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInInvestingActivities_b12a5e2b-e618-467f-a686-cffecc537899" xlink:to="loc_us-gaap_ProceedsFromSaleOfAvailableForSaleSecuritiesDebt_59cf4db7-e132-42a0-8363-ebaebae7803f" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentsToAcquirePropertyPlantAndEquipment_21c9e8ac-beb5-422f-a5b9-70276c2dcef8" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PaymentsToAcquirePropertyPlantAndEquipment"/>
    <link:calculationArc order="3" weight="-1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInInvestingActivities_b12a5e2b-e618-467f-a686-cffecc537899" xlink:to="loc_us-gaap_PaymentsToAcquirePropertyPlantAndEquipment_21c9e8ac-beb5-422f-a5b9-70276c2dcef8" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_cass_DecreaseIncreaseInPaymentsInAdvanceOfFunding_264d8b89-2f8e-41c3-ba62-e8c244cc0916" xlink:href="cass-20240930.xsd#cass_DecreaseIncreaseInPaymentsInAdvanceOfFunding"/>
    <link:calculationArc order="4" weight="-1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInInvestingActivities_b12a5e2b-e618-467f-a686-cffecc537899" xlink:to="loc_cass_DecreaseIncreaseInPaymentsInAdvanceOfFunding_264d8b89-2f8e-41c3-ba62-e8c244cc0916" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentsForProceedsFromLoansAndLeases_e8514365-8ad6-4ad6-9a15-b16d2b94fe19" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PaymentsForProceedsFromLoansAndLeases"/>
    <link:calculationArc order="5" weight="-1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInInvestingActivities_b12a5e2b-e618-467f-a686-cffecc537899" xlink:to="loc_us-gaap_PaymentsForProceedsFromLoansAndLeases_e8514365-8ad6-4ad6-9a15-b16d2b94fe19" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentsToAcquireAvailableForSaleSecuritiesDebt_12e86418-cabd-457a-8aa5-8b77ff2f8d55" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PaymentsToAcquireAvailableForSaleSecuritiesDebt"/>
    <link:calculationArc order="6" weight="-1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInInvestingActivities_b12a5e2b-e618-467f-a686-cffecc537899" xlink:to="loc_us-gaap_PaymentsToAcquireAvailableForSaleSecuritiesDebt_12e86418-cabd-457a-8aa5-8b77ff2f8d55" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseExcludingExchangeRateEffect_22a8e782-ea7c-49eb-ab5d-6e856f2ff7a4" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseExcludingExchangeRateEffect"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_3bc996cb-5bf5-4d21-86fc-c27e7b534f1b" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_NetCashProvidedByUsedInOperatingActivities"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseExcludingExchangeRateEffect_22a8e782-ea7c-49eb-ab5d-6e856f2ff7a4" xlink:to="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_3bc996cb-5bf5-4d21-86fc-c27e7b534f1b" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetCashProvidedByUsedInInvestingActivities_44dac4fb-6596-495a-81b5-c1ec6e035d7c" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_NetCashProvidedByUsedInInvestingActivities"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseExcludingExchangeRateEffect_22a8e782-ea7c-49eb-ab5d-6e856f2ff7a4" xlink:to="loc_us-gaap_NetCashProvidedByUsedInInvestingActivities_44dac4fb-6596-495a-81b5-c1ec6e035d7c" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetCashProvidedByUsedInFinancingActivities_a1667d05-c049-40f8-b80d-34616b154e8a" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_NetCashProvidedByUsedInFinancingActivities"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseExcludingExchangeRateEffect_22a8e782-ea7c-49eb-ab5d-6e856f2ff7a4" xlink:to="loc_us-gaap_NetCashProvidedByUsedInFinancingActivities_a1667d05-c049-40f8-b80d-34616b154e8a" xlink:type="arc"/>
  </link:calculationLink>
  <link:roleRef roleURI="http://cassinfo.com/role/IntangibleAssetsScheduleofIntangibleAssetsandGoodwillDetails" xlink:type="simple" xlink:href="cass-20240930.xsd#IntangibleAssetsScheduleofIntangibleAssetsandGoodwillDetails"/>
  <link:calculationLink xlink:role="http://cassinfo.com/role/IntangibleAssetsScheduleofIntangibleAssetsandGoodwillDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IntangibleAssetsNetIncludingGoodwill_6262225c-35f7-46d9-b173-a8ec8d38e207" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_IntangibleAssetsNetIncludingGoodwill"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GoodwillGross_726850ef-6409-4a67-b64e-035e3da09b41" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_GoodwillGross"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_IntangibleAssetsNetIncludingGoodwill_6262225c-35f7-46d9-b173-a8ec8d38e207" xlink:to="loc_us-gaap_GoodwillGross_726850ef-6409-4a67-b64e-035e3da09b41" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsGross_0ce4b79f-6069-47e6-9dd7-5929e24b805b" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_FiniteLivedIntangibleAssetsGross"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_IntangibleAssetsNetIncludingGoodwill_6262225c-35f7-46d9-b173-a8ec8d38e207" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsGross_0ce4b79f-6069-47e6-9dd7-5929e24b805b" xlink:type="arc"/>
  </link:calculationLink>
  <link:roleRef roleURI="http://cassinfo.com/role/EarningsPerShareDetails" xlink:type="simple" xlink:href="cass-20240930.xsd#EarningsPerShareDetails"/>
  <link:calculationLink xlink:role="http://cassinfo.com/role/EarningsPerShareDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding_e6d3b5ba-de3c-46c1-be6b-dfb70998c57e" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_WeightedAverageNumberOfSharesOutstandingBasic_e7d2b8a1-df90-4e93-be41-c47585f283c7" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_WeightedAverageNumberOfSharesOutstandingBasic"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding_e6d3b5ba-de3c-46c1-be6b-dfb70998c57e" xlink:to="loc_us-gaap_WeightedAverageNumberOfSharesOutstandingBasic_e7d2b8a1-df90-4e93-be41-c47585f283c7" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_WeightedAverageNumberDilutedSharesOutstandingAdjustment_db5b45fa-2617-42d9-ab33-0a8b013084cc" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_WeightedAverageNumberDilutedSharesOutstandingAdjustment"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding_e6d3b5ba-de3c-46c1-be6b-dfb70998c57e" xlink:to="loc_us-gaap_WeightedAverageNumberDilutedSharesOutstandingAdjustment_db5b45fa-2617-42d9-ab33-0a8b013084cc" xlink:type="arc"/>
  </link:calculationLink>
  <link:roleRef roleURI="http://cassinfo.com/role/DefinedPensionPlansScheduleofNetPeriodicPensionCostsDetails" xlink:type="simple" xlink:href="cass-20240930.xsd#DefinedPensionPlansScheduleofNetPeriodicPensionCostsDetails"/>
  <link:calculationLink xlink:role="http://cassinfo.com/role/DefinedPensionPlansScheduleofNetPeriodicPensionCostsDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanNetPeriodicBenefitCost_68e92c74-0d7a-4f71-bf94-766f4c5e3a18" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DefinedBenefitPlanNetPeriodicBenefitCost"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanInterestCost_576e6156-9dd6-4677-b257-842cac6b1c82" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DefinedBenefitPlanInterestCost"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_DefinedBenefitPlanNetPeriodicBenefitCost_68e92c74-0d7a-4f71-bf94-766f4c5e3a18" xlink:to="loc_us-gaap_DefinedBenefitPlanInterestCost_576e6156-9dd6-4677-b257-842cac6b1c82" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanExpectedReturnOnPlanAssets_a3ad104a-5c1c-450f-93e9-6741226aff4a" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DefinedBenefitPlanExpectedReturnOnPlanAssets"/>
    <link:calculationArc order="2" weight="-1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_DefinedBenefitPlanNetPeriodicBenefitCost_68e92c74-0d7a-4f71-bf94-766f4c5e3a18" xlink:to="loc_us-gaap_DefinedBenefitPlanExpectedReturnOnPlanAssets_a3ad104a-5c1c-450f-93e9-6741226aff4a" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanAmortizationOfPriorServiceCostCredit_0d0a693a-b32a-4f4c-9f8f-f73c97d80390" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DefinedBenefitPlanAmortizationOfPriorServiceCostCredit"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_DefinedBenefitPlanNetPeriodicBenefitCost_68e92c74-0d7a-4f71-bf94-766f4c5e3a18" xlink:to="loc_us-gaap_DefinedBenefitPlanAmortizationOfPriorServiceCostCredit_0d0a693a-b32a-4f4c-9f8f-f73c97d80390" xlink:type="arc"/>
  </link:calculationLink>
  <link:roleRef roleURI="http://cassinfo.com/role/InvestmentinSecuritiesScheduleofInvestmentSecuritiesDetails" xlink:type="simple" xlink:href="cass-20240930.xsd#InvestmentinSecuritiesScheduleofInvestmentSecuritiesDetails"/>
  <link:calculationLink xlink:role="http://cassinfo.com/role/InvestmentinSecuritiesScheduleofInvestmentSecuritiesDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtSecuritiesAvailableForSaleAmortizedCostExcludingAccruedInterestAfterAllowanceForCreditLoss_41aa3d46-7614-48e1-903c-03b72eaf7e46" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DebtSecuritiesAvailableForSaleAmortizedCostExcludingAccruedInterestAfterAllowanceForCreditLoss"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtSecuritiesAvailableForSaleExcludingAccruedInterest_ca098796-9d6b-477a-a0df-98f98bc9d5bb" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DebtSecuritiesAvailableForSaleExcludingAccruedInterest"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_DebtSecuritiesAvailableForSaleAmortizedCostExcludingAccruedInterestAfterAllowanceForCreditLoss_41aa3d46-7614-48e1-903c-03b72eaf7e46" xlink:to="loc_us-gaap_DebtSecuritiesAvailableForSaleExcludingAccruedInterest_ca098796-9d6b-477a-a0df-98f98bc9d5bb" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedLossBeforeTax_30170a4d-8589-45b1-b3e1-c46983d28b2f" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedLossBeforeTax"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_DebtSecuritiesAvailableForSaleAmortizedCostExcludingAccruedInterestAfterAllowanceForCreditLoss_41aa3d46-7614-48e1-903c-03b72eaf7e46" xlink:to="loc_us-gaap_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedLossBeforeTax_30170a4d-8589-45b1-b3e1-c46983d28b2f" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedGainBeforeTax_d3835234-0ef6-417c-b77c-105815399f53" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedGainBeforeTax"/>
    <link:calculationArc order="3" weight="-1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_DebtSecuritiesAvailableForSaleAmortizedCostExcludingAccruedInterestAfterAllowanceForCreditLoss_41aa3d46-7614-48e1-903c-03b72eaf7e46" xlink:to="loc_us-gaap_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedGainBeforeTax_d3835234-0ef6-417c-b77c-105815399f53" xlink:type="arc"/>
  </link:calculationLink>
  <link:roleRef roleURI="http://cassinfo.com/role/InvestmentinSecuritiesScheduleoftheFairValuesofSecuritieswithUnrealizedLossesDetails" xlink:type="simple" xlink:href="cass-20240930.xsd#InvestmentinSecuritiesScheduleoftheFairValuesofSecuritieswithUnrealizedLossesDetails"/>
  <link:calculationLink xlink:role="http://cassinfo.com/role/InvestmentinSecuritiesScheduleoftheFairValuesofSecuritieswithUnrealizedLossesDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtSecuritiesAvailableForSaleUnrealizedLossPositionAccumulatedLoss_ae4f08e8-5257-4df5-a5ab-a2a45562ade3" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DebtSecuritiesAvailableForSaleUnrealizedLossPositionAccumulatedLoss"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPosition12MonthsOrLongerAccumulatedLoss_bb63aee5-f5a3-4860-8dc5-3851d034d89c" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPosition12MonthsOrLongerAccumulatedLoss"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_DebtSecuritiesAvailableForSaleUnrealizedLossPositionAccumulatedLoss_ae4f08e8-5257-4df5-a5ab-a2a45562ade3" xlink:to="loc_us-gaap_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPosition12MonthsOrLongerAccumulatedLoss_bb63aee5-f5a3-4860-8dc5-3851d034d89c" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12MonthsAccumulatedLoss_3c0a9a82-3d0d-4b66-93fa-d65c14dcd5fe" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12MonthsAccumulatedLoss"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_DebtSecuritiesAvailableForSaleUnrealizedLossPositionAccumulatedLoss_ae4f08e8-5257-4df5-a5ab-a2a45562ade3" xlink:to="loc_us-gaap_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12MonthsAccumulatedLoss_3c0a9a82-3d0d-4b66-93fa-d65c14dcd5fe" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtSecuritiesAvailableForSaleUnrealizedLossPosition_baee885f-1cb4-4b3f-bbb8-9936f4012a2a" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DebtSecuritiesAvailableForSaleUnrealizedLossPosition"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12Months_0ec266b4-d413-43b9-957f-f7c297de5afe" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12Months"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_DebtSecuritiesAvailableForSaleUnrealizedLossPosition_baee885f-1cb4-4b3f-bbb8-9936f4012a2a" xlink:to="loc_us-gaap_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12Months_0ec266b4-d413-43b9-957f-f7c297de5afe" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPosition12MonthsOrLonger_257d3358-1535-41b0-9018-af78f9f78588" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPosition12MonthsOrLonger"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_DebtSecuritiesAvailableForSaleUnrealizedLossPosition_baee885f-1cb4-4b3f-bbb8-9936f4012a2a" xlink:to="loc_us-gaap_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPosition12MonthsOrLonger_257d3358-1535-41b0-9018-af78f9f78588" xlink:type="arc"/>
  </link:calculationLink>
  <link:roleRef roleURI="http://cassinfo.com/role/InvestmentinSecuritiesScheduleofAmortizedCostandFairValueofInvestmentSecuritiesDetails" xlink:type="simple" xlink:href="cass-20240930.xsd#InvestmentinSecuritiesScheduleofAmortizedCostandFairValueofInvestmentSecuritiesDetails"/>
  <link:calculationLink xlink:role="http://cassinfo.com/role/InvestmentinSecuritiesScheduleofAmortizedCostandFairValueofInvestmentSecuritiesDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtSecuritiesAvailableForSaleAmortizedCostExcludingAccruedInterestAfterAllowanceForCreditLoss_6be254dc-925f-428c-bad8-9600bbdba408" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DebtSecuritiesAvailableForSaleAmortizedCostExcludingAccruedInterestAfterAllowanceForCreditLoss"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterOneThroughFiveYearsAmortizedCost_35486df0-9f11-468f-ae17-7089fa15289d" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterOneThroughFiveYearsAmortizedCost"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_DebtSecuritiesAvailableForSaleAmortizedCostExcludingAccruedInterestAfterAllowanceForCreditLoss_6be254dc-925f-428c-bad8-9600bbdba408" xlink:to="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterOneThroughFiveYearsAmortizedCost_35486df0-9f11-468f-ae17-7089fa15289d" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterFiveThroughTenYearsAmortizedCost_6e480cc9-ae65-48e0-ae15-e88b19d6cf62" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterFiveThroughTenYearsAmortizedCost"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_DebtSecuritiesAvailableForSaleAmortizedCostExcludingAccruedInterestAfterAllowanceForCreditLoss_6be254dc-925f-428c-bad8-9600bbdba408" xlink:to="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterFiveThroughTenYearsAmortizedCost_6e480cc9-ae65-48e0-ae15-e88b19d6cf62" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesWithinOneYearAmortizedCost_b0937e8f-bb5f-4e2d-8d5c-fa463f87b828" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_AvailableForSaleSecuritiesDebtMaturitiesWithinOneYearAmortizedCost"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_DebtSecuritiesAvailableForSaleAmortizedCostExcludingAccruedInterestAfterAllowanceForCreditLoss_6be254dc-925f-428c-bad8-9600bbdba408" xlink:to="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesWithinOneYearAmortizedCost_b0937e8f-bb5f-4e2d-8d5c-fa463f87b828" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterTenYearsAmortizedCost_4b323dc0-2321-456d-8ce4-cdd38f083940" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterTenYearsAmortizedCost"/>
    <link:calculationArc order="4" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_DebtSecuritiesAvailableForSaleAmortizedCostExcludingAccruedInterestAfterAllowanceForCreditLoss_6be254dc-925f-428c-bad8-9600bbdba408" xlink:to="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterTenYearsAmortizedCost_4b323dc0-2321-456d-8ce4-cdd38f083940" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtSecuritiesAvailableForSaleExcludingAccruedInterest_cfa50de7-2a76-43d6-a048-04117ccb053c" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DebtSecuritiesAvailableForSaleExcludingAccruedInterest"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesWithinOneYearFairValue_772afc07-7d47-48ab-8b7a-fccfea406e0e" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_AvailableForSaleSecuritiesDebtMaturitiesWithinOneYearFairValue"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_DebtSecuritiesAvailableForSaleExcludingAccruedInterest_cfa50de7-2a76-43d6-a048-04117ccb053c" xlink:to="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesWithinOneYearFairValue_772afc07-7d47-48ab-8b7a-fccfea406e0e" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterOneThroughFiveYearsFairValue_da8b148e-6322-4fa9-b7aa-7a563345320a" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterOneThroughFiveYearsFairValue"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_DebtSecuritiesAvailableForSaleExcludingAccruedInterest_cfa50de7-2a76-43d6-a048-04117ccb053c" xlink:to="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterOneThroughFiveYearsFairValue_da8b148e-6322-4fa9-b7aa-7a563345320a" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterFiveThroughTenYearsFairValue_f9703425-945c-4646-a44c-89084e8ff68b" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterFiveThroughTenYearsFairValue"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_DebtSecuritiesAvailableForSaleExcludingAccruedInterest_cfa50de7-2a76-43d6-a048-04117ccb053c" xlink:to="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterFiveThroughTenYearsFairValue_f9703425-945c-4646-a44c-89084e8ff68b" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterTenYearsFairValue_a244508d-0bb6-4c3c-a43b-c3fb9cbb5086" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterTenYearsFairValue"/>
    <link:calculationArc order="4" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_DebtSecuritiesAvailableForSaleExcludingAccruedInterest_cfa50de7-2a76-43d6-a048-04117ccb053c" xlink:to="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterTenYearsFairValue_a244508d-0bb6-4c3c-a43b-c3fb9cbb5086" xlink:type="arc"/>
  </link:calculationLink>
  <link:roleRef roleURI="http://cassinfo.com/role/FairValueofFinancialInstrumentsDetails" xlink:type="simple" xlink:href="cass-20240930.xsd#FairValueofFinancialInstrumentsDetails"/>
  <link:calculationLink xlink:role="http://cassinfo.com/role/FairValueofFinancialInstrumentsDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LiabilitiesFairValueDisclosure_cf740426-512c-4939-8ccf-126f73e9615c" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LiabilitiesFairValueDisclosure"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DepositsFairValueDisclosure_cd922dbf-179e-41fa-ab6c-a34579bc9c98" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DepositsFairValueDisclosure"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_LiabilitiesFairValueDisclosure_cf740426-512c-4939-8ccf-126f73e9615c" xlink:to="loc_us-gaap_DepositsFairValueDisclosure_cd922dbf-179e-41fa-ab6c-a34579bc9c98" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccountsPayableFairValueDisclosure_fb7e2a2f-30d4-4f58-b466-c9854df4cc05" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_AccountsPayableFairValueDisclosure"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_LiabilitiesFairValueDisclosure_cf740426-512c-4939-8ccf-126f73e9615c" xlink:to="loc_us-gaap_AccountsPayableFairValueDisclosure_fb7e2a2f-30d4-4f58-b466-c9854df4cc05" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccruedLiabilitiesFairValueDisclosure_aa0a076f-9994-4032-8da0-f9338e8b62ae" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_AccruedLiabilitiesFairValueDisclosure"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_LiabilitiesFairValueDisclosure_cf740426-512c-4939-8ccf-126f73e9615c" xlink:to="loc_us-gaap_AccruedLiabilitiesFairValueDisclosure_aa0a076f-9994-4032-8da0-f9338e8b62ae" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AssetsFairValueDisclosure_57c89fb9-9f69-4ddb-81b6-297986c3d400" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_AssetsFairValueDisclosure"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtSecuritiesAvailableForSaleExcludingAccruedInterest_b8303caa-8185-436d-995f-2593de29e6b2" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DebtSecuritiesAvailableForSaleExcludingAccruedInterest"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_AssetsFairValueDisclosure_57c89fb9-9f69-4ddb-81b6-297986c3d400" xlink:to="loc_us-gaap_DebtSecuritiesAvailableForSaleExcludingAccruedInterest_b8303caa-8185-436d-995f-2593de29e6b2" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CashAndCashEquivalentsFairValueDisclosure_c7fac85f-5b66-48a4-a923-b8d92c51703c" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CashAndCashEquivalentsFairValueDisclosure"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_AssetsFairValueDisclosure_57c89fb9-9f69-4ddb-81b6-297986c3d400" xlink:to="loc_us-gaap_CashAndCashEquivalentsFairValueDisclosure_c7fac85f-5b66-48a4-a923-b8d92c51703c" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LoansReceivableFairValueDisclosure_3b9476d3-4af7-40bd-a3e5-0639fd27313b" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LoansReceivableFairValueDisclosure"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_AssetsFairValueDisclosure_57c89fb9-9f69-4ddb-81b6-297986c3d400" xlink:to="loc_us-gaap_LoansReceivableFairValueDisclosure_3b9476d3-4af7-40bd-a3e5-0639fd27313b" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_cass_AccruedInterestReceivableFairValueDisclosure_3595eb36-5cba-41ba-aff4-1b270382b414" xlink:href="cass-20240930.xsd#cass_AccruedInterestReceivableFairValueDisclosure"/>
    <link:calculationArc order="4" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_AssetsFairValueDisclosure_57c89fb9-9f69-4ddb-81b6-297986c3d400" xlink:to="loc_cass_AccruedInterestReceivableFairValueDisclosure_3595eb36-5cba-41ba-aff4-1b270382b414" xlink:type="arc"/>
  </link:calculationLink>
  <link:roleRef roleURI="http://cassinfo.com/role/RevenuefromContractswithCustomersDetails" xlink:type="simple" xlink:href="cass-20240930.xsd#RevenuefromContractswithCustomersDetails"/>
  <link:calculationLink xlink:role="http://cassinfo.com/role/RevenuefromContractswithCustomersDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NoninterestIncome_028c3eff-1ca8-4b16-9b6c-c5581a6001bc" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_NoninterestIncome"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueNotFromContractWithCustomer_a314558a-cb9d-41e1-b258-a49a747c4318" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_RevenueNotFromContractWithCustomer"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NoninterestIncome_028c3eff-1ca8-4b16-9b6c-c5581a6001bc" xlink:to="loc_us-gaap_RevenueNotFromContractWithCustomer_a314558a-cb9d-41e1-b258-a49a747c4318" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_1d6214a2-e286-4b98-9bc7-cce75b334e4d" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NoninterestIncome_028c3eff-1ca8-4b16-9b6c-c5581a6001bc" xlink:to="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_1d6214a2-e286-4b98-9bc7-cce75b334e4d" xlink:type="arc"/>
  </link:calculationLink>
  <link:roleRef roleURI="http://cassinfo.com/role/LeasesScheduleofOperatingLeaseMaturityDetails" xlink:type="simple" xlink:href="cass-20240930.xsd#LeasesScheduleofOperatingLeaseMaturityDetails"/>
  <link:calculationLink xlink:role="http://cassinfo.com/role/LeasesScheduleofOperatingLeaseMaturityDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDue_71ea6d84-dc64-40f7-b287-026e0461a995" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LesseeOperatingLeaseLiabilityPaymentsDue"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingLeaseLiability_6f2412f0-f097-498f-9849-afda23f02980" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_OperatingLeaseLiability"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDue_71ea6d84-dc64-40f7-b287-026e0461a995" xlink:to="loc_us-gaap_OperatingLeaseLiability_6f2412f0-f097-498f-9849-afda23f02980" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LesseeOperatingLeaseLiabilityUndiscountedExcessAmount_e4cec48d-faf6-42be-87a9-a9087c653d92" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LesseeOperatingLeaseLiabilityUndiscountedExcessAmount"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDue_71ea6d84-dc64-40f7-b287-026e0461a995" xlink:to="loc_us-gaap_LesseeOperatingLeaseLiabilityUndiscountedExcessAmount_e4cec48d-faf6-42be-87a9-a9087c653d92" xlink:type="arc"/>
  </link:calculationLink>
  <link:roleRef roleURI="http://cassinfo.com/role/LeasesScheduleofOperatingLeaseMaturityDetails_1" xlink:type="simple" xlink:href="cass-20240930.xsd#LeasesScheduleofOperatingLeaseMaturityDetails_1"/>
  <link:calculationLink xlink:role="http://cassinfo.com/role/LeasesScheduleofOperatingLeaseMaturityDetails_1" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDue_13abead5-ef6b-47cb-9c89-66c9685bf1ad" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LesseeOperatingLeaseLiabilityPaymentsDue"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LesseeOperatingLeaseLiabilityPaymentsRemainderOfFiscalYear_1fe870a1-178f-4a46-849a-b5e8fabf3444" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LesseeOperatingLeaseLiabilityPaymentsRemainderOfFiscalYear"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDue_13abead5-ef6b-47cb-9c89-66c9685bf1ad" xlink:to="loc_us-gaap_LesseeOperatingLeaseLiabilityPaymentsRemainderOfFiscalYear_1fe870a1-178f-4a46-849a-b5e8fabf3444" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueNextTwelveMonths_6689d7e3-46d1-418e-b81d-8efe4808d2c0" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueNextTwelveMonths"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDue_13abead5-ef6b-47cb-9c89-66c9685bf1ad" xlink:to="loc_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueNextTwelveMonths_6689d7e3-46d1-418e-b81d-8efe4808d2c0" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearTwo_199c1f9f-8f8a-43c2-a65b-1ee04c35e95d" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearTwo"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDue_13abead5-ef6b-47cb-9c89-66c9685bf1ad" xlink:to="loc_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearTwo_199c1f9f-8f8a-43c2-a65b-1ee04c35e95d" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearThree_0578ee92-6b15-4e88-8f2c-677c19c51ce8" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearThree"/>
    <link:calculationArc order="4" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDue_13abead5-ef6b-47cb-9c89-66c9685bf1ad" xlink:to="loc_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearThree_0578ee92-6b15-4e88-8f2c-677c19c51ce8" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearFour_3acca8a7-4bf9-4a0c-bc8c-d707429ebfeb" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearFour"/>
    <link:calculationArc order="5" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDue_13abead5-ef6b-47cb-9c89-66c9685bf1ad" xlink:to="loc_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearFour_3acca8a7-4bf9-4a0c-bc8c-d707429ebfeb" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_cass_LesseeOperatingLeaseLiabilityToBePaidDueAfterYearFour_45cc21ac-96d3-4c11-864a-8540815b5921" xlink:href="cass-20240930.xsd#cass_LesseeOperatingLeaseLiabilityToBePaidDueAfterYearFour"/>
    <link:calculationArc order="6" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDue_13abead5-ef6b-47cb-9c89-66c9685bf1ad" xlink:to="loc_cass_LesseeOperatingLeaseLiabilityToBePaidDueAfterYearFour_45cc21ac-96d3-4c11-864a-8540815b5921" xlink:type="arc"/>
  </link:calculationLink>
</link:linkbase>
