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

<!--XBRL Document Created with the Workiva Platform-->
<!--Copyright 2026 Workiva-->
<!--r:019e41e0-c180-79b0-9a83-ba25ac545b6d,g:92126a41-5611-4ed7-b2be-9b46fb2bc9a8-->
<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:arcroleRef arcroleURI="https://xbrl.org/2023/arcrole/summation-item" xlink:type="simple" xlink:href="https://www.xbrl.org/2023/calculation-1.1.xsd#summation-item"/>
  <link:roleRef roleURI="http://www.tandemdiabetes.com/role/CONDENSEDCONSOLIDATEDBALANCESHEETS" xlink:type="simple" xlink:href="tndm-20260630.xsd#CONDENSEDCONSOLIDATEDBALANCESHEETS"/>
  <link:calculationLink xlink:role="http://www.tandemdiabetes.com/role/CONDENSEDCONSOLIDATEDBALANCESHEETS" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AssetsCurrent_019e41e0-c3b4-7a9c-baf0-ff0b1aa0170a" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AssetsCurrent"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CashAndCashEquivalentsAtCarryingValue_019e41e0-c3b4-7c28-8090-a6082bb46a25" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CashAndCashEquivalentsAtCarryingValue"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_AssetsCurrent_019e41e0-c3b4-7a9c-baf0-ff0b1aa0170a" xlink:to="loc_us-gaap_CashAndCashEquivalentsAtCarryingValue_019e41e0-c3b4-7c28-8090-a6082bb46a25" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShortTermInvestments_019e41e0-c3b4-776e-bba2-3407de871f04" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShortTermInvestments"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_AssetsCurrent_019e41e0-c3b4-7a9c-baf0-ff0b1aa0170a" xlink:to="loc_us-gaap_ShortTermInvestments_019e41e0-c3b4-776e-bba2-3407de871f04" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccountsReceivableNetCurrent_019e41e0-c3b4-79c9-bdca-b2e6b753fe3c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AccountsReceivableNetCurrent"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_AssetsCurrent_019e41e0-c3b4-7a9c-baf0-ff0b1aa0170a" xlink:to="loc_us-gaap_AccountsReceivableNetCurrent_019e41e0-c3b4-79c9-bdca-b2e6b753fe3c" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InventoryNet_019e41e0-c3b4-7340-a237-301699d43c4f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InventoryNet"/>
    <link:calculationArc order="4" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_AssetsCurrent_019e41e0-c3b4-7a9c-baf0-ff0b1aa0170a" xlink:to="loc_us-gaap_InventoryNet_019e41e0-c3b4-7340-a237-301699d43c4f" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PrepaidExpenseAndOtherAssetsCurrent_019e41e0-c3b4-7437-bb30-84002e868d5b" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PrepaidExpenseAndOtherAssetsCurrent"/>
    <link:calculationArc order="5" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_AssetsCurrent_019e41e0-c3b4-7a9c-baf0-ff0b1aa0170a" xlink:to="loc_us-gaap_PrepaidExpenseAndOtherAssetsCurrent_019e41e0-c3b4-7437-bb30-84002e868d5b" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LiabilitiesAndStockholdersEquity_019e41e0-c3b4-7f3a-a0e5-528fbe9dde22" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LiabilitiesAndStockholdersEquity"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Liabilities_019e41e0-c3b4-7f87-816d-9396211adf6b" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_Liabilities"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquity_019e41e0-c3b4-7f3a-a0e5-528fbe9dde22" xlink:to="loc_us-gaap_Liabilities_019e41e0-c3b4-7f87-816d-9396211adf6b" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommitmentsAndContingencies_019e41e0-c3b4-73aa-ae31-d0ae66e4459d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CommitmentsAndContingencies"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquity_019e41e0-c3b4-7f3a-a0e5-528fbe9dde22" xlink:to="loc_us-gaap_CommitmentsAndContingencies_019e41e0-c3b4-73aa-ae31-d0ae66e4459d" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquity_019e41e0-c3b4-7f38-a1c6-ef0b69dd9ee3" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StockholdersEquity"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquity_019e41e0-c3b4-7f3a-a0e5-528fbe9dde22" xlink:to="loc_us-gaap_StockholdersEquity_019e41e0-c3b4-7f38-a1c6-ef0b69dd9ee3" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LiabilitiesCurrent_019e41e0-c3b4-7926-8edb-c2c12290aff7" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LiabilitiesCurrent"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccountsPayableCurrent_019e41e0-c3b4-76e2-9fde-340f086bfb0e" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AccountsPayableCurrent"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_LiabilitiesCurrent_019e41e0-c3b4-7926-8edb-c2c12290aff7" xlink:to="loc_us-gaap_AccountsPayableCurrent_019e41e0-c3b4-76e2-9fde-340f086bfb0e" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccruedLiabilitiesCurrent_019e41e0-c3b4-73fc-a5ad-02933b1afe39" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AccruedLiabilitiesCurrent"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_LiabilitiesCurrent_019e41e0-c3b4-7926-8edb-c2c12290aff7" xlink:to="loc_us-gaap_AccruedLiabilitiesCurrent_019e41e0-c3b4-73fc-a5ad-02933b1afe39" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EmployeeRelatedLiabilitiesCurrent_019e41e0-c3b4-72fb-8079-88068964e770" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EmployeeRelatedLiabilitiesCurrent"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_LiabilitiesCurrent_019e41e0-c3b4-7926-8edb-c2c12290aff7" xlink:to="loc_us-gaap_EmployeeRelatedLiabilitiesCurrent_019e41e0-c3b4-72fb-8079-88068964e770" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ContractWithCustomerLiabilityCurrent_019e41e0-c3b4-78f4-869e-c8e773c6981e" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ContractWithCustomerLiabilityCurrent"/>
    <link:calculationArc order="4" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_LiabilitiesCurrent_019e41e0-c3b4-7926-8edb-c2c12290aff7" xlink:to="loc_us-gaap_ContractWithCustomerLiabilityCurrent_019e41e0-c3b4-78f4-869e-c8e773c6981e" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingLeaseLiabilityCurrent_019e41e0-c3b4-7de8-ade0-440b4b59f06a" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OperatingLeaseLiabilityCurrent"/>
    <link:calculationArc order="5" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_LiabilitiesCurrent_019e41e0-c3b4-7926-8edb-c2c12290aff7" xlink:to="loc_us-gaap_OperatingLeaseLiabilityCurrent_019e41e0-c3b4-7de8-ade0-440b4b59f06a" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherLiabilitiesCurrent_019e41e0-c3b4-71ad-b9cf-99868f0045a0" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OtherLiabilitiesCurrent"/>
    <link:calculationArc order="6" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_LiabilitiesCurrent_019e41e0-c3b4-7926-8edb-c2c12290aff7" xlink:to="loc_us-gaap_OtherLiabilitiesCurrent_019e41e0-c3b4-71ad-b9cf-99868f0045a0" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Assets_019e41e0-c3b4-78f0-be0a-bc2856ac2457" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_Assets"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AssetsCurrent_019e41e0-c3b4-7734-aac3-5fed77dc5d09" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AssetsCurrent"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_Assets_019e41e0-c3b4-78f0-be0a-bc2856ac2457" xlink:to="loc_us-gaap_AssetsCurrent_019e41e0-c3b4-7734-aac3-5fed77dc5d09" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingLeaseRightOfUseAsset_019e41e0-c3b4-7e4d-9735-9ceda1c4c494" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OperatingLeaseRightOfUseAsset"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_Assets_019e41e0-c3b4-78f0-be0a-bc2856ac2457" xlink:to="loc_us-gaap_OperatingLeaseRightOfUseAsset_019e41e0-c3b4-7e4d-9735-9ceda1c4c494" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityMethodInvestments_019e41e0-c3b4-7b0e-88a6-c58513e77670" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EquityMethodInvestments"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_Assets_019e41e0-c3b4-78f0-be0a-bc2856ac2457" xlink:to="loc_us-gaap_EquityMethodInvestments_019e41e0-c3b4-7b0e-88a6-c58513e77670" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentNet_019e41e0-c3b4-78b5-a300-f805519c4c1e" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PropertyPlantAndEquipmentNet"/>
    <link:calculationArc order="4" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_Assets_019e41e0-c3b4-78f0-be0a-bc2856ac2457" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentNet_019e41e0-c3b4-78b5-a300-f805519c4c1e" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherAssetsNoncurrent_019e41e0-c3b4-7f4a-a084-8cbe803d802f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OtherAssetsNoncurrent"/>
    <link:calculationArc order="5" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_Assets_019e41e0-c3b4-78f0-be0a-bc2856ac2457" xlink:to="loc_us-gaap_OtherAssetsNoncurrent_019e41e0-c3b4-7f4a-a084-8cbe803d802f" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquity_019e41e0-c3b4-7327-8b96-02a73d86a4c6" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StockholdersEquity"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockValue_019e41e0-c3b4-752c-bbba-f3a700cbafbe" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CommonStockValue"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_StockholdersEquity_019e41e0-c3b4-7327-8b96-02a73d86a4c6" xlink:to="loc_us-gaap_CommonStockValue_019e41e0-c3b4-752c-bbba-f3a700cbafbe" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AdditionalPaidInCapitalCommonStock_019e41e0-c3b4-759d-8c4f-5cb9e43b316e" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AdditionalPaidInCapitalCommonStock"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_StockholdersEquity_019e41e0-c3b4-7327-8b96-02a73d86a4c6" xlink:to="loc_us-gaap_AdditionalPaidInCapitalCommonStock_019e41e0-c3b4-759d-8c4f-5cb9e43b316e" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax_019e41e0-c3b4-79fa-9c6a-be909b752aba" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_StockholdersEquity_019e41e0-c3b4-7327-8b96-02a73d86a4c6" xlink:to="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax_019e41e0-c3b4-79fa-9c6a-be909b752aba" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetainedEarningsAccumulatedDeficit_019e41e0-c3b4-77c1-a5e4-b8641f782a2a" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RetainedEarningsAccumulatedDeficit"/>
    <link:calculationArc order="4" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_StockholdersEquity_019e41e0-c3b4-7327-8b96-02a73d86a4c6" xlink:to="loc_us-gaap_RetainedEarningsAccumulatedDeficit_019e41e0-c3b4-77c1-a5e4-b8641f782a2a" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Liabilities_019e41e0-c3b4-79d8-a8da-ecbe2001f0a3" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_Liabilities"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConvertibleDebtNoncurrent_019e41e0-c3b4-7638-856b-7f4bd366c7ad" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ConvertibleDebtNoncurrent"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_Liabilities_019e41e0-c3b4-79d8-a8da-ecbe2001f0a3" xlink:to="loc_us-gaap_ConvertibleDebtNoncurrent_019e41e0-c3b4-7638-856b-7f4bd366c7ad" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingLeaseLiabilityNoncurrent_019e41e0-c3b4-7298-af57-6450618c05b1" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OperatingLeaseLiabilityNoncurrent"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_Liabilities_019e41e0-c3b4-79d8-a8da-ecbe2001f0a3" xlink:to="loc_us-gaap_OperatingLeaseLiabilityNoncurrent_019e41e0-c3b4-7298-af57-6450618c05b1" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherLiabilitiesNoncurrent_019e41e0-c3b4-7679-9826-65bff179a1df" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OtherLiabilitiesNoncurrent"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_Liabilities_019e41e0-c3b4-79d8-a8da-ecbe2001f0a3" xlink:to="loc_us-gaap_OtherLiabilitiesNoncurrent_019e41e0-c3b4-7679-9826-65bff179a1df" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LiabilitiesCurrent_019e41e0-c3b4-7c3b-8607-6dfbc432d79a" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LiabilitiesCurrent"/>
    <link:calculationArc order="4" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_Liabilities_019e41e0-c3b4-79d8-a8da-ecbe2001f0a3" xlink:to="loc_us-gaap_LiabilitiesCurrent_019e41e0-c3b4-7c3b-8607-6dfbc432d79a" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ContractWithCustomerLiabilityNoncurrent_019e41e0-c3b4-71f9-9d72-1a203ac312ad" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ContractWithCustomerLiabilityNoncurrent"/>
    <link:calculationArc order="5" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_Liabilities_019e41e0-c3b4-79d8-a8da-ecbe2001f0a3" xlink:to="loc_us-gaap_ContractWithCustomerLiabilityNoncurrent_019e41e0-c3b4-71f9-9d72-1a203ac312ad" xlink:type="arc"/>
  </link:calculationLink>
  <link:roleRef roleURI="http://www.tandemdiabetes.com/role/CONDENSEDCONSOLIDATEDSTATEMENTSOFOPERATIONSANDCOMPREHENSIVELOSSUnaudited" xlink:type="simple" xlink:href="tndm-20260630.xsd#CONDENSEDCONSOLIDATEDSTATEMENTSOFOPERATIONSANDCOMPREHENSIVELOSSUnaudited"/>
  <link:calculationLink xlink:role="http://www.tandemdiabetes.com/role/CONDENSEDCONSOLIDATEDSTATEMENTSOFOPERATIONSANDCOMPREHENSIVELOSSUnaudited" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetIncomeLoss_019e41e0-c3b4-7e70-a913-c8315a7ae9e2" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NetIncomeLoss"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest_019e41e0-c3b4-75d8-9199-4ab2b22b4e69" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetIncomeLoss_019e41e0-c3b4-7e70-a913-c8315a7ae9e2" xlink:to="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest_019e41e0-c3b4-75d8-9199-4ab2b22b4e69" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeTaxExpenseBenefit_019e41e0-c3b4-7d9c-aefa-c97def93d30a" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_IncomeTaxExpenseBenefit"/>
    <link:calculationArc order="2" weight="-1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetIncomeLoss_019e41e0-c3b4-7e70-a913-c8315a7ae9e2" xlink:to="loc_us-gaap_IncomeTaxExpenseBenefit_019e41e0-c3b4-7d9c-aefa-c97def93d30a" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ComprehensiveIncomeNetOfTax_019e41e0-c3b4-7211-9c13-7eb83e4639fc" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ComprehensiveIncomeNetOfTax"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetIncomeLoss_019e41e0-c3b4-7100-96dc-db5c36d40308" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NetIncomeLoss"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_ComprehensiveIncomeNetOfTax_019e41e0-c3b4-7211-9c13-7eb83e4639fc" xlink:to="loc_us-gaap_NetIncomeLoss_019e41e0-c3b4-7100-96dc-db5c36d40308" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossAvailableForSaleSecuritiesAdjustmentNetOfTax_019e41e0-c3b4-754c-b3dc-17cdd9735f0c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OtherComprehensiveIncomeLossAvailableForSaleSecuritiesAdjustmentNetOfTax"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_ComprehensiveIncomeNetOfTax_019e41e0-c3b4-7211-9c13-7eb83e4639fc" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossAvailableForSaleSecuritiesAdjustmentNetOfTax_019e41e0-c3b4-754c-b3dc-17cdd9735f0c" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossCashFlowHedgeGainLossAfterReclassificationAndTaxParent_019e41e0-c3b4-7fdd-81db-79a3efd7d2a1" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OtherComprehensiveIncomeLossCashFlowHedgeGainLossAfterReclassificationAndTaxParent"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_ComprehensiveIncomeNetOfTax_019e41e0-c3b4-7211-9c13-7eb83e4639fc" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossCashFlowHedgeGainLossAfterReclassificationAndTaxParent_019e41e0-c3b4-7fdd-81db-79a3efd7d2a1" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeForeignCurrencyTransactionAndTranslationAdjustmentNetOfTaxPortionAttributableToParent_019e41e0-c3b4-76f1-a0a8-df46eada8674" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OtherComprehensiveIncomeForeignCurrencyTransactionAndTranslationAdjustmentNetOfTaxPortionAttributableToParent"/>
    <link:calculationArc order="4" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_ComprehensiveIncomeNetOfTax_019e41e0-c3b4-7211-9c13-7eb83e4639fc" xlink:to="loc_us-gaap_OtherComprehensiveIncomeForeignCurrencyTransactionAndTranslationAdjustmentNetOfTaxPortionAttributableToParent_019e41e0-c3b4-76f1-a0a8-df46eada8674" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest_019e41e0-c3b4-73b2-9257-a64baad0ec8b" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingIncomeLoss_019e41e0-c3b4-7f43-8341-d5b18696ab5b" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OperatingIncomeLoss"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest_019e41e0-c3b4-73b2-9257-a64baad0ec8b" xlink:to="loc_us-gaap_OperatingIncomeLoss_019e41e0-c3b4-7f43-8341-d5b18696ab5b" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherNonoperatingIncomeExpense_019e41e0-c3b4-7332-a58c-d0674aafcb83" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OtherNonoperatingIncomeExpense"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest_019e41e0-c3b4-73b2-9257-a64baad0ec8b" xlink:to="loc_us-gaap_OtherNonoperatingIncomeExpense_019e41e0-c3b4-7332-a58c-d0674aafcb83" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GrossProfit_019e41e0-c3b4-7e3f-922c-a576f8c30b99" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_GrossProfit"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_019e41e0-c3b4-75c5-95a4-7930994ad1af" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_GrossProfit_019e41e0-c3b4-7e3f-922c-a576f8c30b99" xlink:to="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_019e41e0-c3b4-75c5-95a4-7930994ad1af" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CostOfGoodsAndServicesSold_019e41e0-c3b4-7786-8aee-3b6d1386a269" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CostOfGoodsAndServicesSold"/>
    <link:calculationArc order="2" weight="-1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_GrossProfit_019e41e0-c3b4-7e3f-922c-a576f8c30b99" xlink:to="loc_us-gaap_CostOfGoodsAndServicesSold_019e41e0-c3b4-7786-8aee-3b6d1386a269" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingIncomeLoss_019e41e0-c3b4-77eb-8aca-92c943c137b4" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OperatingIncomeLoss"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GrossProfit_019e41e0-c3b4-7544-b3e1-97ccdcd5ab5a" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_GrossProfit"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_OperatingIncomeLoss_019e41e0-c3b4-77eb-8aca-92c943c137b4" xlink:to="loc_us-gaap_GrossProfit_019e41e0-c3b4-7544-b3e1-97ccdcd5ab5a" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingExpenses_019e41e0-c3b4-7319-a244-3506ac1f5394" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OperatingExpenses"/>
    <link:calculationArc order="2" weight="-1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_OperatingIncomeLoss_019e41e0-c3b4-77eb-8aca-92c943c137b4" xlink:to="loc_us-gaap_OperatingExpenses_019e41e0-c3b4-7319-a244-3506ac1f5394" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherNonoperatingIncomeExpense_019e41e0-c3b4-7134-ad95-cdf4ea1ebb2f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OtherNonoperatingIncomeExpense"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestExpenseNonoperating_019e41e0-c3b4-7f16-b241-a7aa6dffab8e" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InterestExpenseNonoperating"/>
    <link:calculationArc order="1" weight="-1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_OtherNonoperatingIncomeExpense_019e41e0-c3b4-7134-ad95-cdf4ea1ebb2f" xlink:to="loc_us-gaap_InterestExpenseNonoperating_019e41e0-c3b4-7f16-b241-a7aa6dffab8e" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeLossFromEquityMethodInvestments_019e41e0-c3b4-72c1-8529-a41eb1a94745" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_IncomeLossFromEquityMethodInvestments"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_OtherNonoperatingIncomeExpense_019e41e0-c3b4-7134-ad95-cdf4ea1ebb2f" xlink:to="loc_us-gaap_IncomeLossFromEquityMethodInvestments_019e41e0-c3b4-72c1-8529-a41eb1a94745" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_tndm_InterestIncomeAndOtherIncomeExpenseNet_019e41e0-c3b4-7d2c-bcc4-d3f774341c5f" xlink:href="tndm-20260630.xsd#tndm_InterestIncomeAndOtherIncomeExpenseNet"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_OtherNonoperatingIncomeExpense_019e41e0-c3b4-7134-ad95-cdf4ea1ebb2f" xlink:to="loc_tndm_InterestIncomeAndOtherIncomeExpenseNet_019e41e0-c3b4-7d2c-bcc4-d3f774341c5f" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingExpenses_019e41e0-c3b4-734d-b277-81cc1d9c304c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OperatingExpenses"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SellingGeneralAndAdministrativeExpense_019e41e0-c3b4-7843-9d6b-9237a6453624" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SellingGeneralAndAdministrativeExpense"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_OperatingExpenses_019e41e0-c3b4-734d-b277-81cc1d9c304c" xlink:to="loc_us-gaap_SellingGeneralAndAdministrativeExpense_019e41e0-c3b4-7843-9d6b-9237a6453624" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ResearchAndDevelopmentExpenseExcludingAcquiredInProcessCost_019e41e0-c3b4-7403-82ce-258635832d2a" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ResearchAndDevelopmentExpenseExcludingAcquiredInProcessCost"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_OperatingExpenses_019e41e0-c3b4-734d-b277-81cc1d9c304c" xlink:to="loc_us-gaap_ResearchAndDevelopmentExpenseExcludingAcquiredInProcessCost_019e41e0-c3b4-7403-82ce-258635832d2a" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ResearchAndDevelopmentAssetAcquiredOtherThanThroughBusinessCombinationWrittenOff_019e41e0-c3b4-7cdc-a646-315a3d596bea" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ResearchAndDevelopmentAssetAcquiredOtherThanThroughBusinessCombinationWrittenOff"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_OperatingExpenses_019e41e0-c3b4-734d-b277-81cc1d9c304c" xlink:to="loc_us-gaap_ResearchAndDevelopmentAssetAcquiredOtherThanThroughBusinessCombinationWrittenOff_019e41e0-c3b4-7cdc-a646-315a3d596bea" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LitigationSettlementExpense_019f0294-bef9-7136-b30e-16bea8d901b1" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LitigationSettlementExpense"/>
    <link:calculationArc order="4" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_OperatingExpenses_019e41e0-c3b4-734d-b277-81cc1d9c304c" xlink:to="loc_us-gaap_LitigationSettlementExpense_019f0294-bef9-7136-b30e-16bea8d901b1" xlink:type="arc"/>
  </link:calculationLink>
  <link:roleRef roleURI="http://www.tandemdiabetes.com/role/CONDENSEDCONSOLIDATEDSTATEMENTSOFCASHFLOWSUnaudited" xlink:type="simple" xlink:href="tndm-20260630.xsd#CONDENSEDCONSOLIDATEDSTATEMENTSOFCASHFLOWSUnaudited"/>
  <link:calculationLink xlink:role="http://www.tandemdiabetes.com/role/CONDENSEDCONSOLIDATEDSTATEMENTSOFCASHFLOWSUnaudited" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetCashProvidedByUsedInInvestingActivities_019e41e0-c3b4-7d10-bf13-176ff29bd9f8" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NetCashProvidedByUsedInInvestingActivities"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentsToAcquireShortTermInvestments_019e41e0-c3b4-7922-bf3b-5e02f4672529" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PaymentsToAcquireShortTermInvestments"/>
    <link:calculationArc order="1" weight="-1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInInvestingActivities_019e41e0-c3b4-7d10-bf13-176ff29bd9f8" xlink:to="loc_us-gaap_PaymentsToAcquireShortTermInvestments_019e41e0-c3b4-7922-bf3b-5e02f4672529" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProceedsFromMaturitiesPrepaymentsAndCallsOfShorttermInvestments_019e41e0-c3b4-7915-a171-cc1468305f08" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ProceedsFromMaturitiesPrepaymentsAndCallsOfShorttermInvestments"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInInvestingActivities_019e41e0-c3b4-7d10-bf13-176ff29bd9f8" xlink:to="loc_us-gaap_ProceedsFromMaturitiesPrepaymentsAndCallsOfShorttermInvestments_019e41e0-c3b4-7915-a171-cc1468305f08" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentsToAcquirePropertyPlantAndEquipment_019e41e0-c3b4-74ad-9724-b2bbb688b05a" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PaymentsToAcquirePropertyPlantAndEquipment"/>
    <link:calculationArc order="3" weight="-1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInInvestingActivities_019e41e0-c3b4-7d10-bf13-176ff29bd9f8" xlink:to="loc_us-gaap_PaymentsToAcquirePropertyPlantAndEquipment_019e41e0-c3b4-74ad-9724-b2bbb688b05a" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentsToAcquireInProcessResearchAndDevelopment_019e41e0-c3b4-705f-a850-35972732d512" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PaymentsToAcquireInProcessResearchAndDevelopment"/>
    <link:calculationArc order="4" weight="-1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInInvestingActivities_019e41e0-c3b4-7d10-bf13-176ff29bd9f8" xlink:to="loc_us-gaap_PaymentsToAcquireInProcessResearchAndDevelopment_019e41e0-c3b4-705f-a850-35972732d512" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_tndm_PaymentsToAcquireIntangibleAssetsAndStrategicInvestments_019f6692-54f5-742b-b93a-80ddfb142115" xlink:href="tndm-20260630.xsd#tndm_PaymentsToAcquireIntangibleAssetsAndStrategicInvestments"/>
    <link:calculationArc order="5" weight="-1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInInvestingActivities_019e41e0-c3b4-7d10-bf13-176ff29bd9f8" xlink:to="loc_tndm_PaymentsToAcquireIntangibleAssetsAndStrategicInvestments_019f6692-54f5-742b-b93a-80ddfb142115" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_019e41e0-c3b4-73b3-b800-eab955a27d05" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NetCashProvidedByUsedInOperatingActivities"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProfitLoss_019e41e0-c3b4-7f3a-b0aa-0ce49434f9cd" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ProfitLoss"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_019e41e0-c3b4-73b3-b800-eab955a27d05" xlink:to="loc_us-gaap_ProfitLoss_019e41e0-c3b4-7f3a-b0aa-0ce49434f9cd" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DepreciationDepletionAndAmortization_019e41e0-c3b4-7515-8247-3c91b6d9854c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DepreciationDepletionAndAmortization"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_019e41e0-c3b4-73b3-b800-eab955a27d05" xlink:to="loc_us-gaap_DepreciationDepletionAndAmortization_019e41e0-c3b4-7515-8247-3c91b6d9854c" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AmortizationOfFinancingCosts_019e41e0-c3b4-71c4-b2d3-560d538c6e41" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AmortizationOfFinancingCosts"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_019e41e0-c3b4-73b3-b800-eab955a27d05" xlink:to="loc_us-gaap_AmortizationOfFinancingCosts_019e41e0-c3b4-71c4-b2d3-560d538c6e41" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProvisionForDoubtfulAccounts_019e41e0-c3b4-7207-83c2-4ac7198b22b2" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ProvisionForDoubtfulAccounts"/>
    <link:calculationArc order="4" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_019e41e0-c3b4-73b3-b800-eab955a27d05" xlink:to="loc_us-gaap_ProvisionForDoubtfulAccounts_019e41e0-c3b4-7207-83c2-4ac7198b22b2" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_tndm_OperatingLeaseImpairmentAndTerminationLoss_019e41e0-c3b4-7d97-9816-9675a9bb50a9" xlink:href="tndm-20260630.xsd#tndm_OperatingLeaseImpairmentAndTerminationLoss"/>
    <link:calculationArc order="5" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_019e41e0-c3b4-73b3-b800-eab955a27d05" xlink:to="loc_tndm_OperatingLeaseImpairmentAndTerminationLoss_019e41e0-c3b4-7d97-9816-9675a9bb50a9" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentIncomeNetAmortizationOfDiscountAndPremium_019e41e0-c3b4-7cc0-8c49-22d45b61926e" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InvestmentIncomeNetAmortizationOfDiscountAndPremium"/>
    <link:calculationArc order="6" weight="-1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_019e41e0-c3b4-73b3-b800-eab955a27d05" xlink:to="loc_us-gaap_InvestmentIncomeNetAmortizationOfDiscountAndPremium_019e41e0-c3b4-7cc0-8c49-22d45b61926e" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeLossFromEquityMethodInvestments_019e41e0-c3b4-7146-86ce-b2606331d8a0" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_IncomeLossFromEquityMethodInvestments"/>
    <link:calculationArc order="7" weight="-1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_019e41e0-c3b4-73b3-b800-eab955a27d05" xlink:to="loc_us-gaap_IncomeLossFromEquityMethodInvestments_019e41e0-c3b4-7146-86ce-b2606331d8a0" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensation_019e41e0-c3b4-75f3-88f5-72bd12db9be0" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensation"/>
    <link:calculationArc order="8" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_019e41e0-c3b4-73b3-b800-eab955a27d05" xlink:to="loc_us-gaap_ShareBasedCompensation_019e41e0-c3b4-75f3-88f5-72bd12db9be0" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ResearchAndDevelopmentAssetAcquiredOtherThanThroughBusinessCombinationWrittenOff_019e41e0-c3b4-7ff2-afca-be3d8bafd336" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ResearchAndDevelopmentAssetAcquiredOtherThanThroughBusinessCombinationWrittenOff"/>
    <link:calculationArc order="9" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_019e41e0-c3b4-73b3-b800-eab955a27d05" xlink:to="loc_us-gaap_ResearchAndDevelopmentAssetAcquiredOtherThanThroughBusinessCombinationWrittenOff_019e41e0-c3b4-7ff2-afca-be3d8bafd336" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherOperatingActivitiesCashFlowStatement_019e41e0-c3b4-702c-a4e8-c2d4f9b6fd84" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OtherOperatingActivitiesCashFlowStatement"/>
    <link:calculationArc order="10" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_019e41e0-c3b4-73b3-b800-eab955a27d05" xlink:to="loc_us-gaap_OtherOperatingActivitiesCashFlowStatement_019e41e0-c3b4-702c-a4e8-c2d4f9b6fd84" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncreaseDecreaseInAccountsReceivable_019e41e0-c3b4-7e8a-b6f1-547c53937767" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_IncreaseDecreaseInAccountsReceivable"/>
    <link:calculationArc order="11" weight="-1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_019e41e0-c3b4-73b3-b800-eab955a27d05" xlink:to="loc_us-gaap_IncreaseDecreaseInAccountsReceivable_019e41e0-c3b4-7e8a-b6f1-547c53937767" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncreaseDecreaseInInventories_019e41e0-c3b4-764f-b06c-ed8b9163290c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_IncreaseDecreaseInInventories"/>
    <link:calculationArc order="12" weight="-1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_019e41e0-c3b4-73b3-b800-eab955a27d05" xlink:to="loc_us-gaap_IncreaseDecreaseInInventories_019e41e0-c3b4-764f-b06c-ed8b9163290c" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncreaseDecreaseInPrepaidDeferredExpenseAndOtherAssets_019e41e0-c3b4-7c1a-9ad5-fb4cdff985ec" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_IncreaseDecreaseInPrepaidDeferredExpenseAndOtherAssets"/>
    <link:calculationArc order="13" weight="-1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_019e41e0-c3b4-73b3-b800-eab955a27d05" xlink:to="loc_us-gaap_IncreaseDecreaseInPrepaidDeferredExpenseAndOtherAssets_019e41e0-c3b4-7c1a-9ad5-fb4cdff985ec" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncreaseDecreaseInOtherNoncurrentAssets_019e41e0-c3b4-74e5-8ac8-76ab5681d245" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_IncreaseDecreaseInOtherNoncurrentAssets"/>
    <link:calculationArc order="14" weight="-1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_019e41e0-c3b4-73b3-b800-eab955a27d05" xlink:to="loc_us-gaap_IncreaseDecreaseInOtherNoncurrentAssets_019e41e0-c3b4-74e5-8ac8-76ab5681d245" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncreaseDecreaseInAccountsPayable_019e41e0-c3b4-7e22-b99e-8762764295d9" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_IncreaseDecreaseInAccountsPayable"/>
    <link:calculationArc order="15" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_019e41e0-c3b4-73b3-b800-eab955a27d05" xlink:to="loc_us-gaap_IncreaseDecreaseInAccountsPayable_019e41e0-c3b4-7e22-b99e-8762764295d9" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncreaseDecreaseInEmployeeRelatedLiabilities_019e41e0-c3b4-7455-aebe-5e1ff650363f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_IncreaseDecreaseInEmployeeRelatedLiabilities"/>
    <link:calculationArc order="16" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_019e41e0-c3b4-73b3-b800-eab955a27d05" xlink:to="loc_us-gaap_IncreaseDecreaseInEmployeeRelatedLiabilities_019e41e0-c3b4-7455-aebe-5e1ff650363f" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncreaseDecreaseInContractWithCustomerLiability_019e41e0-c3b4-76b4-a05b-f1a2d3e82ea7" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_IncreaseDecreaseInContractWithCustomerLiability"/>
    <link:calculationArc order="17" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_019e41e0-c3b4-73b3-b800-eab955a27d05" xlink:to="loc_us-gaap_IncreaseDecreaseInContractWithCustomerLiability_019e41e0-c3b4-76b4-a05b-f1a2d3e82ea7" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncreaseDecreaseInOperatingLeaseLiability_019e41e0-c3b4-724e-a87c-6781249f18c1" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_IncreaseDecreaseInOperatingLeaseLiability"/>
    <link:calculationArc order="18" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_019e41e0-c3b4-73b3-b800-eab955a27d05" xlink:to="loc_us-gaap_IncreaseDecreaseInOperatingLeaseLiability_019e41e0-c3b4-724e-a87c-6781249f18c1" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncreaseDecreaseInOtherNoncurrentLiabilities_019e41e0-c3b4-76a6-80c1-2c8fd61c3406" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_IncreaseDecreaseInOtherNoncurrentLiabilities"/>
    <link:calculationArc order="19" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_019e41e0-c3b4-73b3-b800-eab955a27d05" xlink:to="loc_us-gaap_IncreaseDecreaseInOtherNoncurrentLiabilities_019e41e0-c3b4-76a6-80c1-2c8fd61c3406" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect_019e41e0-c3b4-7cab-b935-4287b318b13b" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_019e41e0-c3b4-786d-a262-d5f242472e37" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NetCashProvidedByUsedInOperatingActivities"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect_019e41e0-c3b4-7cab-b935-4287b318b13b" xlink:to="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_019e41e0-c3b4-786d-a262-d5f242472e37" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetCashProvidedByUsedInInvestingActivities_019e41e0-c3b4-7741-8205-f14bec3743e4" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NetCashProvidedByUsedInInvestingActivities"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect_019e41e0-c3b4-7cab-b935-4287b318b13b" xlink:to="loc_us-gaap_NetCashProvidedByUsedInInvestingActivities_019e41e0-c3b4-7741-8205-f14bec3743e4" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetCashProvidedByUsedInFinancingActivities_019e41e0-c3b4-7c16-8e5f-586689212b55" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NetCashProvidedByUsedInFinancingActivities"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect_019e41e0-c3b4-7cab-b935-4287b318b13b" xlink:to="loc_us-gaap_NetCashProvidedByUsedInFinancingActivities_019e41e0-c3b4-7c16-8e5f-586689212b55" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EffectOfExchangeRateOnCashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents_019e41e0-c3b4-701e-8890-cc13efb77852" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EffectOfExchangeRateOnCashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents"/>
    <link:calculationArc order="4" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect_019e41e0-c3b4-7cab-b935-4287b318b13b" xlink:to="loc_us-gaap_EffectOfExchangeRateOnCashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents_019e41e0-c3b4-701e-8890-cc13efb77852" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetCashProvidedByUsedInFinancingActivities_019e41e0-c3b4-7e44-a245-b7210b07fbce" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NetCashProvidedByUsedInFinancingActivities"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProceedsFromConvertibleDebt_019e41e0-c3b4-7a62-ae9f-3e1e3f159b43" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ProceedsFromConvertibleDebt"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivities_019e41e0-c3b4-7e44-a245-b7210b07fbce" xlink:to="loc_us-gaap_ProceedsFromConvertibleDebt_019e41e0-c3b4-7a62-ae9f-3e1e3f159b43" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RepaymentsOfNotesPayable_019e41e0-c3b4-7247-b03a-f37c181a15cf" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RepaymentsOfNotesPayable"/>
    <link:calculationArc order="2" weight="-1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivities_019e41e0-c3b4-7e44-a245-b7210b07fbce" xlink:to="loc_us-gaap_RepaymentsOfNotesPayable_019e41e0-c3b4-7247-b03a-f37c181a15cf" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_tndm_PaymentsForCappedCallTransactions_019e41e0-c3b4-7b9b-8e21-a2562ad75c71" xlink:href="tndm-20260630.xsd#tndm_PaymentsForCappedCallTransactions"/>
    <link:calculationArc order="3" weight="-1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivities_019e41e0-c3b4-7e44-a245-b7210b07fbce" xlink:to="loc_tndm_PaymentsForCappedCallTransactions_019e41e0-c3b4-7b9b-8e21-a2562ad75c71" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_tndm_PaymentTaxWithholdingShareBasedPaymentArrangementNet_019f02a5-7ad9-7491-872b-20eb564d586a" xlink:href="tndm-20260630.xsd#tndm_PaymentTaxWithholdingShareBasedPaymentArrangementNet"/>
    <link:calculationArc order="4" weight="-1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivities_019e41e0-c3b4-7e44-a245-b7210b07fbce" xlink:to="loc_tndm_PaymentTaxWithholdingShareBasedPaymentArrangementNet_019f02a5-7ad9-7491-872b-20eb564d586a" xlink:type="arc"/>
  </link:calculationLink>
  <link:roleRef roleURI="http://www.tandemdiabetes.com/role/SummaryofSignificantAccountingPoliciesScheduleofReconciliationofChangeinEstimatedWarrantyLiabilitiesDetails" xlink:type="simple" xlink:href="tndm-20260630.xsd#SummaryofSignificantAccountingPoliciesScheduleofReconciliationofChangeinEstimatedWarrantyLiabilitiesDetails"/>
  <link:calculationLink xlink:role="http://www.tandemdiabetes.com/role/SummaryofSignificantAccountingPoliciesScheduleofReconciliationofChangeinEstimatedWarrantyLiabilitiesDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProductWarrantyAccrual_019e41e0-c3b4-79a9-ac22-3d7e7c558b90" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ProductWarrantyAccrual"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProductWarrantyAccrualNoncurrent_019e41e0-c3b4-719f-9e11-dd6b4d5ce50c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ProductWarrantyAccrualNoncurrent"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_ProductWarrantyAccrual_019e41e0-c3b4-79a9-ac22-3d7e7c558b90" xlink:to="loc_us-gaap_ProductWarrantyAccrualNoncurrent_019e41e0-c3b4-719f-9e11-dd6b4d5ce50c" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProductWarrantyAccrualClassifiedCurrent_019e41e0-c3b4-7dd7-b554-3f04b9664b37" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ProductWarrantyAccrualClassifiedCurrent"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_ProductWarrantyAccrual_019e41e0-c3b4-79a9-ac22-3d7e7c558b90" xlink:to="loc_us-gaap_ProductWarrantyAccrualClassifiedCurrent_019e41e0-c3b4-7dd7-b554-3f04b9664b37" xlink:type="arc"/>
  </link:calculationLink>
  <link:roleRef roleURI="http://www.tandemdiabetes.com/role/ShortTermInvestmentsScheduleofEstimatedFairValueofShortTermInvestmentsDetails" xlink:type="simple" xlink:href="tndm-20260630.xsd#ShortTermInvestmentsScheduleofEstimatedFairValueofShortTermInvestmentsDetails"/>
  <link:calculationLink xlink:role="http://www.tandemdiabetes.com/role/ShortTermInvestmentsScheduleofEstimatedFairValueofShortTermInvestmentsDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AvailableForSaleDebtSecuritiesAmortizedCostBasis_019e41e0-c3b4-7780-836d-cb7d0071d863" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AvailableForSaleDebtSecuritiesAmortizedCostBasis"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AvailableForSaleSecuritiesDebtSecurities_019e41e0-c3b4-7cea-ac06-a6e6b21c5cde" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AvailableForSaleSecuritiesDebtSecurities"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_AvailableForSaleDebtSecuritiesAmortizedCostBasis_019e41e0-c3b4-7780-836d-cb7d0071d863" xlink:to="loc_us-gaap_AvailableForSaleSecuritiesDebtSecurities_019e41e0-c3b4-7cea-ac06-a6e6b21c5cde" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedLossBeforeTax_019e41e0-c3b4-7bc4-aefa-c313e387b8d1" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedLossBeforeTax"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_AvailableForSaleDebtSecuritiesAmortizedCostBasis_019e41e0-c3b4-7780-836d-cb7d0071d863" xlink:to="loc_us-gaap_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedLossBeforeTax_019e41e0-c3b4-7bc4-aefa-c313e387b8d1" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedGainBeforeTax_019e41e0-c3b4-7a82-93e8-c2788369e4d7" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedGainBeforeTax"/>
    <link:calculationArc order="3" weight="-1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_AvailableForSaleDebtSecuritiesAmortizedCostBasis_019e41e0-c3b4-7780-836d-cb7d0071d863" xlink:to="loc_us-gaap_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedGainBeforeTax_019e41e0-c3b4-7a82-93e8-c2788369e4d7" xlink:type="arc"/>
  </link:calculationLink>
  <link:roleRef roleURI="http://www.tandemdiabetes.com/role/ShortTermInvestmentsScheduleofContractualMaturitiesofAvailableForSaleDebtSecuritiesDetails" xlink:type="simple" xlink:href="tndm-20260630.xsd#ShortTermInvestmentsScheduleofContractualMaturitiesofAvailableForSaleDebtSecuritiesDetails"/>
  <link:calculationLink xlink:role="http://www.tandemdiabetes.com/role/ShortTermInvestmentsScheduleofContractualMaturitiesofAvailableForSaleDebtSecuritiesDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesSingleMaturityDate_019e41e0-c3b4-73af-91b4-7306713f246d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AvailableForSaleSecuritiesDebtMaturitiesSingleMaturityDate"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesWithinOneYearFairValue_019e41e0-c3b4-7b3e-a585-f681ada91d31" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AvailableForSaleSecuritiesDebtMaturitiesWithinOneYearFairValue"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesSingleMaturityDate_019e41e0-c3b4-73af-91b4-7306713f246d" xlink:to="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesWithinOneYearFairValue_019e41e0-c3b4-7b3e-a585-f681ada91d31" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_tndm_DebtSecuritiesAvailableForSaleFairValueMaturityAllocatedAndSingleMaturityDateAfterYearOneThroughTwo_019e41e0-c3b4-7d98-8450-2b745bf7590b" xlink:href="tndm-20260630.xsd#tndm_DebtSecuritiesAvailableForSaleFairValueMaturityAllocatedAndSingleMaturityDateAfterYearOneThroughTwo"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesSingleMaturityDate_019e41e0-c3b4-73af-91b4-7306713f246d" xlink:to="loc_tndm_DebtSecuritiesAvailableForSaleFairValueMaturityAllocatedAndSingleMaturityDateAfterYearOneThroughTwo_019e41e0-c3b4-7d98-8450-2b745bf7590b" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_tndm_DebtSecuritiesAvailableForSaleFairValueMaturityAllocatedAndSingleMaturityDateAfterYearTwoThroughThree_019e41e0-c3b4-7812-8b6b-92aa656c6d2f" xlink:href="tndm-20260630.xsd#tndm_DebtSecuritiesAvailableForSaleFairValueMaturityAllocatedAndSingleMaturityDateAfterYearTwoThroughThree"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesSingleMaturityDate_019e41e0-c3b4-73af-91b4-7306713f246d" xlink:to="loc_tndm_DebtSecuritiesAvailableForSaleFairValueMaturityAllocatedAndSingleMaturityDateAfterYearTwoThroughThree_019e41e0-c3b4-7812-8b6b-92aa656c6d2f" xlink:type="arc"/>
  </link:calculationLink>
  <link:roleRef roleURI="http://www.tandemdiabetes.com/role/CompositionofCertainFinancialStatementItemsScheduleofAccountsReceivableDetails" xlink:type="simple" xlink:href="tndm-20260630.xsd#CompositionofCertainFinancialStatementItemsScheduleofAccountsReceivableDetails"/>
  <link:calculationLink xlink:role="http://www.tandemdiabetes.com/role/CompositionofCertainFinancialStatementItemsScheduleofAccountsReceivableDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccountsReceivableNet_019e41e0-c3b4-72b0-b9b5-6e696b91800f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AccountsReceivableNet"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccountsReceivableGross_019e41e0-c3b4-729d-9bc3-611fa3c4b8a6" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AccountsReceivableGross"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_AccountsReceivableNet_019e41e0-c3b4-72b0-b9b5-6e696b91800f" xlink:to="loc_us-gaap_AccountsReceivableGross_019e41e0-c3b4-729d-9bc3-611fa3c4b8a6" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AllowanceForDoubtfulAccountsReceivable_019e41e0-c3b4-70e9-b768-31f5d6ebde32" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AllowanceForDoubtfulAccountsReceivable"/>
    <link:calculationArc order="2" weight="-1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_AccountsReceivableNet_019e41e0-c3b4-72b0-b9b5-6e696b91800f" xlink:to="loc_us-gaap_AllowanceForDoubtfulAccountsReceivable_019e41e0-c3b4-70e9-b768-31f5d6ebde32" xlink:type="arc"/>
  </link:calculationLink>
  <link:roleRef roleURI="http://www.tandemdiabetes.com/role/CompositionofCertainFinancialStatementItemsScheduleofInventoryDetails" xlink:type="simple" xlink:href="tndm-20260630.xsd#CompositionofCertainFinancialStatementItemsScheduleofInventoryDetails"/>
  <link:calculationLink xlink:role="http://www.tandemdiabetes.com/role/CompositionofCertainFinancialStatementItemsScheduleofInventoryDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InventoryNet_019e41e0-c3b4-7fd5-8d7a-b6769c519967" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InventoryNet"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InventoryRawMaterials_019e41e0-c3b4-7329-aed0-92fcea69bd21" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InventoryRawMaterials"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_InventoryNet_019e41e0-c3b4-7fd5-8d7a-b6769c519967" xlink:to="loc_us-gaap_InventoryRawMaterials_019e41e0-c3b4-7329-aed0-92fcea69bd21" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InventoryWorkInProcess_019e41e0-c3b4-7755-957c-47bbd035d825" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InventoryWorkInProcess"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_InventoryNet_019e41e0-c3b4-7fd5-8d7a-b6769c519967" xlink:to="loc_us-gaap_InventoryWorkInProcess_019e41e0-c3b4-7755-957c-47bbd035d825" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InventoryFinishedGoods_019e41e0-c3b4-700a-bc39-b5058bc58f52" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InventoryFinishedGoods"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_InventoryNet_019e41e0-c3b4-7fd5-8d7a-b6769c519967" xlink:to="loc_us-gaap_InventoryFinishedGoods_019e41e0-c3b4-700a-bc39-b5058bc58f52" xlink:type="arc"/>
  </link:calculationLink>
  <link:roleRef roleURI="http://www.tandemdiabetes.com/role/FairValueMeasurementsScheduleofFinancialAssetsandLiabilitiesMeasuredatFairValueonRecurringBasisDetails" xlink:type="simple" xlink:href="tndm-20260630.xsd#FairValueMeasurementsScheduleofFinancialAssetsandLiabilitiesMeasuredatFairValueonRecurringBasisDetails"/>
  <link:calculationLink xlink:role="http://www.tandemdiabetes.com/role/FairValueMeasurementsScheduleofFinancialAssetsandLiabilitiesMeasuredatFairValueonRecurringBasisDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AssetsFairValueDisclosure_019e41e0-c3b5-7ca3-96d2-fe6904bb9e6d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AssetsFairValueDisclosure"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CashAndCashEquivalentsFairValueDisclosure_019e41e0-c3b5-7c05-a557-dc726e22c20a" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CashAndCashEquivalentsFairValueDisclosure"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_AssetsFairValueDisclosure_019e41e0-c3b5-7ca3-96d2-fe6904bb9e6d" xlink:to="loc_us-gaap_CashAndCashEquivalentsFairValueDisclosure_019e41e0-c3b5-7c05-a557-dc726e22c20a" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AvailableForSaleSecuritiesDebtSecurities_019e41e0-c3b5-795e-bca3-1d97d1aca21e" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AvailableForSaleSecuritiesDebtSecurities"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_AssetsFairValueDisclosure_019e41e0-c3b5-7ca3-96d2-fe6904bb9e6d" xlink:to="loc_us-gaap_AvailableForSaleSecuritiesDebtSecurities_019e41e0-c3b5-795e-bca3-1d97d1aca21e" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeAssets_019e41e0-c3b5-7692-b031-e779212669d1" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DerivativeAssets"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_AssetsFairValueDisclosure_019e41e0-c3b5-7ca3-96d2-fe6904bb9e6d" xlink:to="loc_us-gaap_DerivativeAssets_019e41e0-c3b5-7692-b031-e779212669d1" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LiabilitiesFairValueDisclosure_019e41e0-c3b5-7909-ad45-bebcd04568e5" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LiabilitiesFairValueDisclosure"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeLiabilities_019e41e0-c3b5-7f38-a2af-b58d00ebe567" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DerivativeLiabilities"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_LiabilitiesFairValueDisclosure_019e41e0-c3b5-7909-ad45-bebcd04568e5" xlink:to="loc_us-gaap_DerivativeLiabilities_019e41e0-c3b5-7f38-a2af-b58d00ebe567" xlink:type="arc"/>
  </link:calculationLink>
  <link:roleRef roleURI="http://www.tandemdiabetes.com/role/LeasesScheduleofLeaseCostDetails" xlink:type="simple" xlink:href="tndm-20260630.xsd#LeasesScheduleofLeaseCostDetails"/>
  <link:calculationLink xlink:role="http://www.tandemdiabetes.com/role/LeasesScheduleofLeaseCostDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LeaseCost_019e41e0-c3b5-7d44-9a7f-5b03bb38db95" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LeaseCost"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingLeaseCost_019e41e0-c3b5-73a3-b895-1215e25fb6c4" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OperatingLeaseCost"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_LeaseCost_019e41e0-c3b5-7d44-9a7f-5b03bb38db95" xlink:to="loc_us-gaap_OperatingLeaseCost_019e41e0-c3b5-73a3-b895-1215e25fb6c4" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShortTermLeaseCost_019e41e0-c3b5-7f26-967f-7c906ed650e1" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShortTermLeaseCost"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_LeaseCost_019e41e0-c3b5-7d44-9a7f-5b03bb38db95" xlink:to="loc_us-gaap_ShortTermLeaseCost_019e41e0-c3b5-7f26-967f-7c906ed650e1" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_tndm_GainLossOnTerminationOfLeaseAndOperatingLeaseImpairmentLoss_019e41e0-c3b5-72c6-99d9-4d6fabea3439" xlink:href="tndm-20260630.xsd#tndm_GainLossOnTerminationOfLeaseAndOperatingLeaseImpairmentLoss"/>
    <link:calculationArc order="3" weight="-1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_LeaseCost_019e41e0-c3b5-7d44-9a7f-5b03bb38db95" xlink:to="loc_tndm_GainLossOnTerminationOfLeaseAndOperatingLeaseImpairmentLoss_019e41e0-c3b5-72c6-99d9-4d6fabea3439" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubleaseIncome_019e41e0-c3b5-7e75-bd6e-6805766e6ef3" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SubleaseIncome"/>
    <link:calculationArc order="4" weight="-1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_LeaseCost_019e41e0-c3b5-7d44-9a7f-5b03bb38db95" xlink:to="loc_us-gaap_SubleaseIncome_019e41e0-c3b5-7e75-bd6e-6805766e6ef3" xlink:type="arc"/>
  </link:calculationLink>
  <link:roleRef roleURI="http://www.tandemdiabetes.com/role/LeasesScheduleofFutureMinimumPaymentsUnderNoncancellableOperatingLeasesDetails" xlink:type="simple" xlink:href="tndm-20260630.xsd#LeasesScheduleofFutureMinimumPaymentsUnderNoncancellableOperatingLeasesDetails"/>
  <link:calculationLink xlink:role="http://www.tandemdiabetes.com/role/LeasesScheduleofFutureMinimumPaymentsUnderNoncancellableOperatingLeasesDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDue_019e41e0-c3b5-7901-8ecc-887528ae57b8" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LesseeOperatingLeaseLiabilityPaymentsDue"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueAfterYearFive_019e41e0-c3b5-7e73-a13a-30f1f5329c7e" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueAfterYearFive"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDue_019e41e0-c3b5-7901-8ecc-887528ae57b8" xlink:to="loc_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueAfterYearFive_019e41e0-c3b5-7e73-a13a-30f1f5329c7e" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueNextTwelveMonths_019e41e0-c3b5-7acc-9322-147137d537e4" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueNextTwelveMonths"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDue_019e41e0-c3b5-7901-8ecc-887528ae57b8" xlink:to="loc_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueNextTwelveMonths_019e41e0-c3b5-7acc-9322-147137d537e4" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearFour_019e41e0-c3b5-7ab6-88d1-3240faaa563c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearFour"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDue_019e41e0-c3b5-7901-8ecc-887528ae57b8" xlink:to="loc_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearFour_019e41e0-c3b5-7ab6-88d1-3240faaa563c" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearThree_019e41e0-c3b5-776a-8600-dca49eed4e46" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearThree"/>
    <link:calculationArc order="4" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDue_019e41e0-c3b5-7901-8ecc-887528ae57b8" xlink:to="loc_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearThree_019e41e0-c3b5-776a-8600-dca49eed4e46" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearTwo_019e41e0-c3b5-778b-a670-ebe13f4f8cf6" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearTwo"/>
    <link:calculationArc order="5" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDue_019e41e0-c3b5-7901-8ecc-887528ae57b8" xlink:to="loc_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearTwo_019e41e0-c3b5-778b-a670-ebe13f4f8cf6" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearFive_019e41e0-c3b5-7f0a-ab07-eaca3bce1a02" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearFive"/>
    <link:calculationArc order="6" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDue_019e41e0-c3b5-7901-8ecc-887528ae57b8" xlink:to="loc_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearFive_019e41e0-c3b5-7f0a-ab07-eaca3bce1a02" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingLeaseLiability_019e41e0-c3b5-7abc-afea-d6e0ee9f5461" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OperatingLeaseLiability"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingLeaseLiabilityNoncurrent_019e41e0-c3b5-7b4f-8bef-b81cdf963592" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OperatingLeaseLiabilityNoncurrent"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_OperatingLeaseLiability_019e41e0-c3b5-7abc-afea-d6e0ee9f5461" xlink:to="loc_us-gaap_OperatingLeaseLiabilityNoncurrent_019e41e0-c3b5-7b4f-8bef-b81cdf963592" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingLeaseLiabilityCurrent_019e41e0-c3b5-70ce-819b-2fba632c8fab" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OperatingLeaseLiabilityCurrent"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_OperatingLeaseLiability_019e41e0-c3b5-7abc-afea-d6e0ee9f5461" xlink:to="loc_us-gaap_OperatingLeaseLiabilityCurrent_019e41e0-c3b5-70ce-819b-2fba632c8fab" xlink:type="arc"/>
  </link:calculationLink>
  <link:roleRef roleURI="http://www.tandemdiabetes.com/role/LeasesScheduleofFutureMinimumPaymentsUnderNoncancellableOperatingLeasesDetails_1" xlink:type="simple" xlink:href="tndm-20260630.xsd#LeasesScheduleofFutureMinimumPaymentsUnderNoncancellableOperatingLeasesDetails_1"/>
  <link:calculationLink xlink:role="http://www.tandemdiabetes.com/role/LeasesScheduleofFutureMinimumPaymentsUnderNoncancellableOperatingLeasesDetails_1" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDue_019e41e0-c3b5-72d5-bbb5-c5ac9daa869f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LesseeOperatingLeaseLiabilityPaymentsDue"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingLeaseLiability_019e41e0-c3b5-7277-924f-cc3d98cb5e34" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OperatingLeaseLiability"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDue_019e41e0-c3b5-72d5-bbb5-c5ac9daa869f" xlink:to="loc_us-gaap_OperatingLeaseLiability_019e41e0-c3b5-7277-924f-cc3d98cb5e34" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LesseeOperatingLeaseLiabilityUndiscountedExcessAmount_019e41e0-c3b5-78cb-9873-dbffa46e1ddb" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LesseeOperatingLeaseLiabilityUndiscountedExcessAmount"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDue_019e41e0-c3b5-72d5-bbb5-c5ac9daa869f" xlink:to="loc_us-gaap_LesseeOperatingLeaseLiabilityUndiscountedExcessAmount_019e41e0-c3b5-78cb-9873-dbffa46e1ddb" xlink:type="arc"/>
  </link:calculationLink>
  <link:roleRef roleURI="http://www.tandemdiabetes.com/role/DebtScheduleofComponentsofConvertibleNoteDetails" xlink:type="simple" xlink:href="tndm-20260630.xsd#DebtScheduleofComponentsofConvertibleNoteDetails"/>
  <link:calculationLink xlink:role="http://www.tandemdiabetes.com/role/DebtScheduleofComponentsofConvertibleNoteDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongTermDebtNoncurrent_019e41e0-c3b5-748b-9ccc-ffc30ae06721" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LongTermDebtNoncurrent"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentFaceAmount_019e41e0-c3b5-7b45-b65e-f8fc32f3788c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtInstrumentFaceAmount"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_LongTermDebtNoncurrent_019e41e0-c3b5-748b-9ccc-ffc30ae06721" xlink:to="loc_us-gaap_DebtInstrumentFaceAmount_019e41e0-c3b5-7b45-b65e-f8fc32f3788c" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DeferredFinanceCostsNet_019e41e0-c3b5-749c-949d-b98ba3e3a54d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DeferredFinanceCostsNet"/>
    <link:calculationArc order="2" weight="-1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_LongTermDebtNoncurrent_019e41e0-c3b5-748b-9ccc-ffc30ae06721" xlink:to="loc_us-gaap_DeferredFinanceCostsNet_019e41e0-c3b5-749c-949d-b98ba3e3a54d" xlink:type="arc"/>
  </link:calculationLink>
  <link:roleRef roleURI="http://www.tandemdiabetes.com/role/DebtScheduleofInterestExpenseRecognizedDetails" xlink:type="simple" xlink:href="tndm-20260630.xsd#DebtScheduleofInterestExpenseRecognizedDetails"/>
  <link:calculationLink xlink:role="http://www.tandemdiabetes.com/role/DebtScheduleofInterestExpenseRecognizedDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestExpenseDebt_019e41e0-c3b5-774d-8268-bdbd964fabed" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InterestExpenseDebt"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AmortizationOfFinancingCosts_019e41e0-c3b5-79d9-8092-f29580dc2c16" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AmortizationOfFinancingCosts"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_InterestExpenseDebt_019e41e0-c3b5-774d-8268-bdbd964fabed" xlink:to="loc_us-gaap_AmortizationOfFinancingCosts_019e41e0-c3b5-79d9-8092-f29580dc2c16" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestExpenseDebtExcludingAmortization_019e41e0-c3b5-797f-9d8c-c0440242c2d7" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InterestExpenseDebtExcludingAmortization"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_InterestExpenseDebt_019e41e0-c3b5-774d-8268-bdbd964fabed" xlink:to="loc_us-gaap_InterestExpenseDebtExcludingAmortization_019e41e0-c3b5-797f-9d8c-c0440242c2d7" xlink:type="arc"/>
  </link:calculationLink>
</link:linkbase>
