<?xml version="1.0" encoding="US-ASCII" standalone="no"?>
    <!-- Field: Doc-Info; Name: Generator; Value: GoFiler Complete; Version: 6.5a -->
    <!-- Field: Doc-Info; Name: VendorURI; Value: https://www.novaworks.com -->
    <!-- Field: Doc-Info; Name: Status; Value: 0x00000000 -->
<link:linkbase xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:link="http://www.xbrl.org/2003/linkbase" xmlns:xbrli="http://www.xbrl.org/2003/instance" xsi:schemaLocation="http://www.xbrl.org/2003/linkbase http://www.xbrl.org/2003/xbrl-linkbase-2003-12-31.xsd">
    <link:roleRef xlink:type="simple" xlink:href="fchs-20260630.xsd#Cover" roleURI="http://myfchs.com/role/Cover" />
    <link:roleRef xlink:type="simple" xlink:href="fchs-20260630.xsd#BalanceSheets" roleURI="http://myfchs.com/role/BalanceSheets" />
    <link:roleRef xlink:type="simple" xlink:href="fchs-20260630.xsd#BalanceSheetsParenthetical" roleURI="http://myfchs.com/role/BalanceSheetsParenthetical" />
    <link:roleRef xlink:type="simple" xlink:href="fchs-20260630.xsd#StatementsOfOperations" roleURI="http://myfchs.com/role/StatementsOfOperations" />
    <link:roleRef xlink:type="simple" xlink:href="fchs-20260630.xsd#StatementOfStockholdersDeficit" roleURI="http://myfchs.com/role/StatementOfStockholdersDeficit" />
    <link:roleRef xlink:type="simple" xlink:href="fchs-20260630.xsd#StatementsOfCashFlows" roleURI="http://myfchs.com/role/StatementsOfCashFlows" />
    <link:roleRef xlink:type="simple" xlink:href="fchs-20260630.xsd#OrganizationBusinessAndPrinciplesOfConsolidation" roleURI="http://myfchs.com/role/OrganizationBusinessAndPrinciplesOfConsolidation" />
    <link:roleRef xlink:type="simple" xlink:href="fchs-20260630.xsd#SignificantAccountingPolicies" roleURI="http://myfchs.com/role/SignificantAccountingPolicies" />
    <link:roleRef xlink:type="simple" xlink:href="fchs-20260630.xsd#NotesPayable" roleURI="http://myfchs.com/role/NotesPayable" />
    <link:roleRef xlink:type="simple" xlink:href="fchs-20260630.xsd#Leases" roleURI="http://myfchs.com/role/Leases" />
    <link:roleRef xlink:type="simple" xlink:href="fchs-20260630.xsd#CapitalStock" roleURI="http://myfchs.com/role/CapitalStock" />
    <link:roleRef xlink:type="simple" xlink:href="fchs-20260630.xsd#StockOptionsWarrantsAndRestrictedStockUnits" roleURI="http://myfchs.com/role/StockOptionsWarrantsAndRestrictedStockUnits" />
    <link:roleRef xlink:type="simple" xlink:href="fchs-20260630.xsd#GoingConcern" roleURI="http://myfchs.com/role/GoingConcern" />
    <link:roleRef xlink:type="simple" xlink:href="fchs-20260630.xsd#SubsequentEvents" roleURI="http://myfchs.com/role/SubsequentEvents" />
    <link:roleRef xlink:type="simple" xlink:href="fchs-20260630.xsd#SignificantAccountingPoliciesPolicies" roleURI="http://myfchs.com/role/SignificantAccountingPoliciesPolicies" />
    <link:roleRef xlink:type="simple" xlink:href="fchs-20260630.xsd#SignificantAccountingPoliciesTables" roleURI="http://myfchs.com/role/SignificantAccountingPoliciesTables" />
    <link:roleRef xlink:type="simple" xlink:href="fchs-20260630.xsd#NotesPayableTables" roleURI="http://myfchs.com/role/NotesPayableTables" />
    <link:roleRef xlink:type="simple" xlink:href="fchs-20260630.xsd#LeasesTables" roleURI="http://myfchs.com/role/LeasesTables" />
    <link:roleRef xlink:type="simple" xlink:href="fchs-20260630.xsd#StockOptionsWarrantsAndRestrictedStockUnitsTables" roleURI="http://myfchs.com/role/StockOptionsWarrantsAndRestrictedStockUnitsTables" />
    <link:roleRef xlink:type="simple" xlink:href="fchs-20260630.xsd#ScheduleOfBasicNetLossPerCommonShareDetails" roleURI="http://myfchs.com/role/ScheduleOfBasicNetLossPerCommonShareDetails" />
    <link:roleRef xlink:type="simple" xlink:href="fchs-20260630.xsd#ScheduleOfAnti-dilutiveWeightedAverageNumberOfCommonSharesOutstandingDetails" roleURI="http://myfchs.com/role/ScheduleOfAnti-dilutiveWeightedAverageNumberOfCommonSharesOutstandingDetails" />
    <link:roleRef xlink:type="simple" xlink:href="fchs-20260630.xsd#SignificantAccountingPoliciesDetailsNarrative" roleURI="http://myfchs.com/role/SignificantAccountingPoliciesDetailsNarrative" />
    <link:roleRef xlink:type="simple" xlink:href="fchs-20260630.xsd#ScheduleOfNonConvertibleNotesPayableDetails" roleURI="http://myfchs.com/role/ScheduleOfNonConvertibleNotesPayableDetails" />
    <link:roleRef xlink:type="simple" xlink:href="fchs-20260630.xsd#ScheduleOfConvertibleNotesPayableDetails" roleURI="http://myfchs.com/role/ScheduleOfConvertibleNotesPayableDetails" />
    <link:roleRef xlink:type="simple" xlink:href="fchs-20260630.xsd#ScheduleOfConvertibleNotesPayableDetailsParenthetical" roleURI="http://myfchs.com/role/ScheduleOfConvertibleNotesPayableDetailsParenthetical" />
    <link:roleRef xlink:type="simple" xlink:href="fchs-20260630.xsd#NotesPayableDetailsNarrative" roleURI="http://myfchs.com/role/NotesPayableDetailsNarrative" />
    <link:roleRef xlink:type="simple" xlink:href="fchs-20260630.xsd#ScheduleOfTerminationOfLeaseDetails" roleURI="http://myfchs.com/role/ScheduleOfTerminationOfLeaseDetails" />
    <link:roleRef xlink:type="simple" xlink:href="fchs-20260630.xsd#ScheduleOfRentInstallmentPaymentsDetails" roleURI="http://myfchs.com/role/ScheduleOfRentInstallmentPaymentsDetails" />
    <link:roleRef xlink:type="simple" xlink:href="fchs-20260630.xsd#LeasesDetailsNarrative" roleURI="http://myfchs.com/role/LeasesDetailsNarrative" />
    <link:roleRef xlink:type="simple" xlink:href="fchs-20260630.xsd#CapitalStockDetailsNarrative" roleURI="http://myfchs.com/role/CapitalStockDetailsNarrative" />
    <link:roleRef xlink:type="simple" xlink:href="fchs-20260630.xsd#StockOptionsWarrantsAndRestrictedStockUnitsDetailsNarrative" roleURI="http://myfchs.com/role/StockOptionsWarrantsAndRestrictedStockUnitsDetailsNarrative" />
    <link:roleRef xlink:type="simple" xlink:href="fchs-20260630.xsd#ScheduleOfWarrantsOutstandingDetails" roleURI="http://myfchs.com/role/ScheduleOfWarrantsOutstandingDetails" />
    <link:roleRef xlink:type="simple" xlink:href="fchs-20260630.xsd#ScheduleOfStockWarrantIssuedDetails" roleURI="http://myfchs.com/role/ScheduleOfStockWarrantIssuedDetails" />
    <link:roleRef xlink:type="simple" xlink:href="fchs-20260630.xsd#GoingConcernDetailsNarrative" roleURI="http://myfchs.com/role/GoingConcernDetailsNarrative" />
    <link:calculationLink xlink:type="extended" xlink:role="http://myfchs.com/role/Cover" xlink:title="00000001 - Document - Cover" />
    <link:calculationLink xlink:type="extended" xlink:role="http://myfchs.com/role/BalanceSheets" xlink:title="00000002 - Statement - Condensed Consolidated Balance Sheets">
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AssetsCurrent" xlink:label="loc_us-gaapAssetsCurrent" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CashAndCashEquivalentsAtCarryingValue" xlink:label="loc_us-gaapCashAndCashEquivalentsAtCarryingValue" />
      <link:calculationArc order="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaapAssetsCurrent" xlink:to="loc_us-gaapCashAndCashEquivalentsAtCarryingValue" xlink:type="arc" weight="1" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AccountsReceivableNetCurrent" xlink:label="loc_us-gaapAccountsReceivableNetCurrent" />
      <link:calculationArc order="2" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaapAssetsCurrent" xlink:to="loc_us-gaapAccountsReceivableNetCurrent" xlink:type="arc" weight="1" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_Assets" xlink:label="loc_us-gaapAssets" />
      <link:calculationArc order="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaapAssets" xlink:to="loc_us-gaapAssetsCurrent" xlink:type="arc" weight="1" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PropertyPlantAndEquipmentNet" xlink:label="loc_us-gaapPropertyPlantAndEquipmentNet" />
      <link:calculationArc order="2" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaapAssets" xlink:to="loc_us-gaapPropertyPlantAndEquipmentNet" xlink:type="arc" weight="1" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OperatingLeaseRightOfUseAsset" xlink:label="loc_us-gaapOperatingLeaseRightOfUseAsset" />
      <link:calculationArc order="3" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaapAssets" xlink:to="loc_us-gaapOperatingLeaseRightOfUseAsset" xlink:type="arc" weight="1" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DepositAssets" xlink:label="loc_us-gaapDepositAssets" />
      <link:calculationArc order="4" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaapAssets" xlink:to="loc_us-gaapDepositAssets" xlink:type="arc" weight="1" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LiabilitiesCurrent" xlink:label="loc_us-gaapLiabilitiesCurrent" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AccountsPayableAndAccruedLiabilitiesCurrent" xlink:label="loc_us-gaapAccountsPayableAndAccruedLiabilitiesCurrent" />
      <link:calculationArc order="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaapLiabilitiesCurrent" xlink:to="loc_us-gaapAccountsPayableAndAccruedLiabilitiesCurrent" xlink:type="arc" weight="1" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OperatingLeaseLiabilityCurrent" xlink:label="loc_us-gaapOperatingLeaseLiabilityCurrent" />
      <link:calculationArc order="2" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaapLiabilitiesCurrent" xlink:to="loc_us-gaapOperatingLeaseLiabilityCurrent" xlink:type="arc" weight="1" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NotesPayableCurrent" xlink:label="loc_us-gaapNotesPayableCurrent" />
      <link:calculationArc order="3" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaapLiabilitiesCurrent" xlink:to="loc_us-gaapNotesPayableCurrent" xlink:type="arc" weight="1" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_Liabilities" xlink:label="loc_us-gaapLiabilities" />
      <link:calculationArc order="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaapLiabilities" xlink:to="loc_us-gaapLiabilitiesCurrent" xlink:type="arc" weight="1" />
      <link:loc xlink:type="locator" xlink:href="fchs-20260630.xsd#FCHS_PaycheckProtectionPlanLoanPayableNoncurrent" xlink:label="loc_FCHSPaycheckProtectionPlanLoanPayableNoncurrent" />
      <link:calculationArc order="2" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaapLiabilities" xlink:to="loc_FCHSPaycheckProtectionPlanLoanPayableNoncurrent" xlink:type="arc" weight="1" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OperatingLeaseLiabilityNoncurrent" xlink:label="loc_us-gaapOperatingLeaseLiabilityNoncurrent" />
      <link:calculationArc order="3" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaapLiabilities" xlink:to="loc_us-gaapOperatingLeaseLiabilityNoncurrent" xlink:type="arc" weight="1" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StockholdersEquity" xlink:label="loc_us-gaapStockholdersEquity" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PreferredStockValue" xlink:label="loc_us-gaapPreferredStockValue" />
      <link:calculationArc order="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaapStockholdersEquity" xlink:to="loc_us-gaapPreferredStockValue" xlink:type="arc" weight="1" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CommonStockValue" xlink:label="loc_us-gaapCommonStockValue" />
      <link:calculationArc order="2" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaapStockholdersEquity" xlink:to="loc_us-gaapCommonStockValue" xlink:type="arc" weight="1" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AdditionalPaidInCapital" xlink:label="loc_us-gaapAdditionalPaidInCapital" />
      <link:calculationArc order="3" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaapStockholdersEquity" xlink:to="loc_us-gaapAdditionalPaidInCapital" xlink:type="arc" weight="1" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_TreasuryStockValue" xlink:label="loc_us-gaapTreasuryStockValue" />
      <link:calculationArc order="4" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaapStockholdersEquity" xlink:to="loc_us-gaapTreasuryStockValue" xlink:type="arc" weight="-1" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RetainedEarningsAccumulatedDeficit" xlink:label="loc_us-gaapRetainedEarningsAccumulatedDeficit" />
      <link:calculationArc order="5" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaapStockholdersEquity" xlink:to="loc_us-gaapRetainedEarningsAccumulatedDeficit" xlink:type="arc" weight="1" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LiabilitiesAndStockholdersEquity" xlink:label="loc_us-gaapLiabilitiesAndStockholdersEquity" />
      <link:calculationArc order="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaapLiabilitiesAndStockholdersEquity" xlink:to="loc_us-gaapLiabilities" xlink:type="arc" weight="1" />
      <link:calculationArc order="2" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaapLiabilitiesAndStockholdersEquity" xlink:to="loc_us-gaapStockholdersEquity" xlink:type="arc" weight="1" />
    </link:calculationLink>
    <link:calculationLink xlink:type="extended" xlink:role="http://myfchs.com/role/BalanceSheetsParenthetical" xlink:title="00000003 - Statement - Condensed Consolidated Balance Sheets (Parenthetical)" />
    <link:calculationLink xlink:type="extended" xlink:role="http://myfchs.com/role/StatementsOfOperations" xlink:title="00000004 - Statement - Condensed Consolidated Statements of Operations (Unaudited)">
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_GrossProfit" xlink:label="loc_us-gaapGrossProfit" />
      <link:loc xlink:type="locator" xlink:href="fchs-20260630.xsd#FCHS_RevenueNetOfDiscounts" xlink:label="loc_FCHSRevenueNetOfDiscounts" />
      <link:calculationArc order="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaapGrossProfit" xlink:to="loc_FCHSRevenueNetOfDiscounts" xlink:type="arc" weight="1" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OperatingExpenses" xlink:label="loc_us-gaapOperatingExpenses" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CompensationExpenseExcludingCostOfGoodAndServiceSold" xlink:label="loc_us-gaapCompensationExpenseExcludingCostOfGoodAndServiceSold" />
      <link:calculationArc order="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaapOperatingExpenses" xlink:to="loc_us-gaapCompensationExpenseExcludingCostOfGoodAndServiceSold" xlink:type="arc" weight="1" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SellingGeneralAndAdministrativeExpense" xlink:label="loc_us-gaapSellingGeneralAndAdministrativeExpense" />
      <link:calculationArc order="2" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaapOperatingExpenses" xlink:to="loc_us-gaapSellingGeneralAndAdministrativeExpense" xlink:type="arc" weight="1" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OperatingIncomeLoss" xlink:label="loc_us-gaapOperatingIncomeLoss" />
      <link:calculationArc order="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaapOperatingIncomeLoss" xlink:to="loc_us-gaapGrossProfit" xlink:type="arc" weight="1" />
      <link:calculationArc order="2" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaapOperatingIncomeLoss" xlink:to="loc_us-gaapOperatingExpenses" xlink:type="arc" weight="-1" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NonoperatingIncomeExpense" xlink:label="loc_us-gaapNonoperatingIncomeExpense" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OtherNonoperatingIncomeExpense" xlink:label="loc_us-gaapOtherNonoperatingIncomeExpense" />
      <link:calculationArc order="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaapNonoperatingIncomeExpense" xlink:to="loc_us-gaapOtherNonoperatingIncomeExpense" xlink:type="arc" weight="1" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_GainLossOnSaleOfPropertyPlantEquipment" xlink:label="loc_us-gaapGainLossOnSaleOfPropertyPlantEquipment" />
      <link:calculationArc order="2" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaapNonoperatingIncomeExpense" xlink:to="loc_us-gaapGainLossOnSaleOfPropertyPlantEquipment" xlink:type="arc" weight="1" />
      <link:loc xlink:type="locator" xlink:href="fchs-20260630.xsd#FCHS_DepositWrittenOff" xlink:label="loc_FCHSDepositWrittenOff" />
      <link:calculationArc order="3" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaapNonoperatingIncomeExpense" xlink:to="loc_FCHSDepositWrittenOff" xlink:type="arc" weight="-1" />
      <link:loc xlink:type="locator" xlink:href="fchs-20260630.xsd#FCHS_ForgivenessOfPaycheckProtectionProgramLoan" xlink:label="loc_FCHSForgivenessOfPaycheckProtectionProgramLoan" />
      <link:calculationArc order="4" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaapNonoperatingIncomeExpense" xlink:to="loc_FCHSForgivenessOfPaycheckProtectionProgramLoan" xlink:type="arc" weight="1" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_GainLossOnTerminationOfLease" xlink:label="loc_us-gaapGainLossOnTerminationOfLease" />
      <link:calculationArc order="5" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaapNonoperatingIncomeExpense" xlink:to="loc_us-gaapGainLossOnTerminationOfLease" xlink:type="arc" weight="1" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InterestExpenseNonoperating" xlink:label="loc_us-gaapInterestExpenseNonoperating" />
      <link:calculationArc order="6" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaapNonoperatingIncomeExpense" xlink:to="loc_us-gaapInterestExpenseNonoperating" xlink:type="arc" weight="-1" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest" xlink:label="loc_us-gaapIncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest" />
      <link:calculationArc order="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaapIncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest" xlink:to="loc_us-gaapOperatingIncomeLoss" xlink:type="arc" weight="1" />
      <link:calculationArc order="2" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaapIncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest" xlink:to="loc_us-gaapNonoperatingIncomeExpense" xlink:type="arc" weight="1" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NetIncomeLoss" xlink:label="loc_us-gaapNetIncomeLoss" />
      <link:calculationArc order="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaapNetIncomeLoss" xlink:to="loc_us-gaapIncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest" xlink:type="arc" weight="1" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_IncomeTaxExpenseBenefit" xlink:label="loc_us-gaapIncomeTaxExpenseBenefit" />
      <link:calculationArc order="2" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaapNetIncomeLoss" xlink:to="loc_us-gaapIncomeTaxExpenseBenefit" xlink:type="arc" weight="-1" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NetIncomeLossAvailableToCommonStockholdersBasic" xlink:label="loc_us-gaapNetIncomeLossAvailableToCommonStockholdersBasic" />
      <link:calculationArc order="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaapNetIncomeLossAvailableToCommonStockholdersBasic" xlink:to="loc_us-gaapNetIncomeLoss" xlink:type="arc" weight="1" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DividendsPreferredStock" xlink:label="loc_us-gaapDividendsPreferredStock" />
      <link:calculationArc order="2" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaapNetIncomeLossAvailableToCommonStockholdersBasic" xlink:to="loc_us-gaapDividendsPreferredStock" xlink:type="arc" weight="-1" />
    </link:calculationLink>
    <link:calculationLink xlink:type="extended" xlink:role="http://myfchs.com/role/StatementOfStockholdersDeficit" xlink:title="00000005 - Statement - Condensed Consolidated Statement of Stockholders&apos; Deficit (Unaudited)" />
    <link:calculationLink xlink:type="extended" xlink:role="http://myfchs.com/role/StatementsOfCashFlows" xlink:title="00000006 - Statement - Condensed Consolidated Statements of Cash Flows (Unaudited)">
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NetCashProvidedByUsedInOperatingActivities" xlink:label="loc_us-gaapNetCashProvidedByUsedInOperatingActivities" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NetIncomeLoss" xlink:label="loc_us-gaapNetIncomeLoss" />
      <link:calculationArc order="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaapNetCashProvidedByUsedInOperatingActivities" xlink:to="loc_us-gaapNetIncomeLoss" xlink:type="arc" weight="1" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DepreciationDepletionAndAmortization" xlink:label="loc_us-gaapDepreciationDepletionAndAmortization" />
      <link:calculationArc order="2" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaapNetCashProvidedByUsedInOperatingActivities" xlink:to="loc_us-gaapDepreciationDepletionAndAmortization" xlink:type="arc" weight="1" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_GainLossOnDispositionOfAssets1" xlink:label="loc_us-gaapGainLossOnDispositionOfAssets1" />
      <link:calculationArc order="3" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaapNetCashProvidedByUsedInOperatingActivities" xlink:to="loc_us-gaapGainLossOnDispositionOfAssets1" xlink:type="arc" weight="-1" />
      <link:loc xlink:type="locator" xlink:href="fchs-20260630.xsd#FCHS_ForgivenessOfPaycheckProtectionProgramLoan" xlink:label="loc_FCHSForgivenessOfPaycheckProtectionProgramLoan" />
      <link:calculationArc order="4" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaapNetCashProvidedByUsedInOperatingActivities" xlink:to="loc_FCHSForgivenessOfPaycheckProtectionProgramLoan" xlink:type="arc" weight="-1" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InterestExpense" xlink:label="loc_us-gaapInterestExpense" />
      <link:calculationArc order="5" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaapNetCashProvidedByUsedInOperatingActivities" xlink:to="loc_us-gaapInterestExpense" xlink:type="arc" weight="1" />
      <link:loc xlink:type="locator" xlink:href="fchs-20260630.xsd#FCHS_DepositsWrittenOff" xlink:label="loc_FCHSDepositsWrittenOff" />
      <link:calculationArc order="6" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaapNetCashProvidedByUsedInOperatingActivities" xlink:to="loc_FCHSDepositsWrittenOff" xlink:type="arc" weight="1" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_GainLossOnTerminationOfLease" xlink:label="loc_us-gaapGainLossOnTerminationOfLease" />
      <link:calculationArc order="7" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaapNetCashProvidedByUsedInOperatingActivities" xlink:to="loc_us-gaapGainLossOnTerminationOfLease" xlink:type="arc" weight="-1" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_IncreaseDecreaseInOtherCurrentAssets" xlink:label="loc_us-gaapIncreaseDecreaseInOtherCurrentAssets" />
      <link:calculationArc order="8" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaapNetCashProvidedByUsedInOperatingActivities" xlink:to="loc_us-gaapIncreaseDecreaseInOtherCurrentAssets" xlink:type="arc" weight="-1" />
      <link:loc xlink:type="locator" xlink:href="fchs-20260630.xsd#FCHS_IncreaseDecreaseInLeasedAssets" xlink:label="loc_FCHSIncreaseDecreaseInLeasedAssets" />
      <link:calculationArc order="9" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaapNetCashProvidedByUsedInOperatingActivities" xlink:to="loc_FCHSIncreaseDecreaseInLeasedAssets" xlink:type="arc" weight="-1" />
      <link:loc xlink:type="locator" xlink:href="fchs-20260630.xsd#FCHS_IncreaseDecreaseInLeaseLiabilities" xlink:label="loc_FCHSIncreaseDecreaseInLeaseLiabilities" />
      <link:calculationArc order="10" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaapNetCashProvidedByUsedInOperatingActivities" xlink:to="loc_FCHSIncreaseDecreaseInLeaseLiabilities" xlink:type="arc" weight="-1" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NetCashProvidedByUsedInInvestingActivities" xlink:label="loc_us-gaapNetCashProvidedByUsedInInvestingActivities" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ProceedsFromSaleOfPropertyPlantAndEquipment" xlink:label="loc_us-gaapProceedsFromSaleOfPropertyPlantAndEquipment" />
      <link:calculationArc order="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaapNetCashProvidedByUsedInInvestingActivities" xlink:to="loc_us-gaapProceedsFromSaleOfPropertyPlantAndEquipment" xlink:type="arc" weight="1" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NetCashProvidedByUsedInFinancingActivities" xlink:label="loc_us-gaapNetCashProvidedByUsedInFinancingActivities" />
      <link:loc xlink:type="locator" xlink:href="fchs-20260630.xsd#FCHS_InterestPaidFromFinancingActivities" xlink:label="loc_FCHSInterestPaidFromFinancingActivities" />
      <link:calculationArc order="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaapNetCashProvidedByUsedInFinancingActivities" xlink:to="loc_FCHSInterestPaidFromFinancingActivities" xlink:type="arc" weight="-1" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RepaymentsOfNotesPayable" xlink:label="loc_us-gaapRepaymentsOfNotesPayable" />
      <link:calculationArc order="2" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaapNetCashProvidedByUsedInFinancingActivities" xlink:to="loc_us-gaapRepaymentsOfNotesPayable" xlink:type="arc" weight="-1" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ProceedsFromConvertibleDebt" xlink:label="loc_us-gaapProceedsFromConvertibleDebt" />
      <link:calculationArc order="3" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaapNetCashProvidedByUsedInFinancingActivities" xlink:to="loc_us-gaapProceedsFromConvertibleDebt" xlink:type="arc" weight="1" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect" xlink:label="loc_us-gaapCashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect" />
      <link:calculationArc order="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaapCashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect" xlink:to="loc_us-gaapNetCashProvidedByUsedInOperatingActivities" xlink:type="arc" weight="1" />
      <link:calculationArc order="2" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaapCashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect" xlink:to="loc_us-gaapNetCashProvidedByUsedInInvestingActivities" xlink:type="arc" weight="1" />
      <link:calculationArc order="3" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaapCashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect" xlink:to="loc_us-gaapNetCashProvidedByUsedInFinancingActivities" xlink:type="arc" weight="1" />
    </link:calculationLink>
    <link:calculationLink xlink:type="extended" xlink:role="http://myfchs.com/role/OrganizationBusinessAndPrinciplesOfConsolidation" xlink:title="999007 - Disclosure - ORGANIZATION, BUSINESS AND PRINCIPLES OF CONSOLIDATION" />
    <link:calculationLink xlink:type="extended" xlink:role="http://myfchs.com/role/SignificantAccountingPolicies" xlink:title="999008 - Disclosure - SIGNIFICANT ACCOUNTING POLICIES" />
    <link:calculationLink xlink:type="extended" xlink:role="http://myfchs.com/role/NotesPayable" xlink:title="999009 - Disclosure - NOTES PAYABLE" />
    <link:calculationLink xlink:type="extended" xlink:role="http://myfchs.com/role/Leases" xlink:title="999010 - Disclosure - LEASES" />
    <link:calculationLink xlink:type="extended" xlink:role="http://myfchs.com/role/CapitalStock" xlink:title="999011 - Disclosure - CAPITAL STOCK" />
    <link:calculationLink xlink:type="extended" xlink:role="http://myfchs.com/role/StockOptionsWarrantsAndRestrictedStockUnits" xlink:title="999012 - Disclosure - STOCK OPTIONS, WARRANTS AND RESTRICTED STOCK UNITS" />
    <link:calculationLink xlink:type="extended" xlink:role="http://myfchs.com/role/GoingConcern" xlink:title="999013 - Disclosure - GOING CONCERN" />
    <link:calculationLink xlink:type="extended" xlink:role="http://myfchs.com/role/SubsequentEvents" xlink:title="999014 - Disclosure - SUBSEQUENT EVENTS" />
    <link:calculationLink xlink:type="extended" xlink:role="http://myfchs.com/role/SignificantAccountingPoliciesPolicies" xlink:title="999015 - Disclosure - SIGNIFICANT ACCOUNTING POLICIES (Policies)" />
    <link:calculationLink xlink:type="extended" xlink:role="http://myfchs.com/role/SignificantAccountingPoliciesTables" xlink:title="999016 - Disclosure - SIGNIFICANT ACCOUNTING POLICIES (Tables)" />
    <link:calculationLink xlink:type="extended" xlink:role="http://myfchs.com/role/NotesPayableTables" xlink:title="999017 - Disclosure - NOTES PAYABLE (Tables)" />
    <link:calculationLink xlink:type="extended" xlink:role="http://myfchs.com/role/LeasesTables" xlink:title="999018 - Disclosure - LEASES (Tables)" />
    <link:calculationLink xlink:type="extended" xlink:role="http://myfchs.com/role/StockOptionsWarrantsAndRestrictedStockUnitsTables" xlink:title="999019 - Disclosure - STOCK OPTIONS, WARRANTS AND RESTRICTED STOCK UNITS (Tables)" />
    <link:calculationLink xlink:type="extended" xlink:role="http://myfchs.com/role/ScheduleOfBasicNetLossPerCommonShareDetails" xlink:title="999020 - Disclosure - SCHEDULE OF BASIC NET LOSS PER COMMON SHARE (Details)" />
    <link:calculationLink xlink:type="extended" xlink:role="http://myfchs.com/role/ScheduleOfAnti-dilutiveWeightedAverageNumberOfCommonSharesOutstandingDetails" xlink:title="999021 - Disclosure - SCHEDULE OF ANTI-DILUTIVE WEIGHTED AVERAGE NUMBER OF COMMON SHARES OUTSTANDING (Details)" />
    <link:calculationLink xlink:type="extended" xlink:role="http://myfchs.com/role/SignificantAccountingPoliciesDetailsNarrative" xlink:title="999022 - Disclosure - SIGNIFICANT ACCOUNTING POLICIES (Details Narrative)" />
    <link:calculationLink xlink:type="extended" xlink:role="http://myfchs.com/role/ScheduleOfNonConvertibleNotesPayableDetails" xlink:title="999023 - Disclosure - SCHEDULE OF NON CONVERTIBLE NOTES PAYABLE (Details)" />
    <link:calculationLink xlink:type="extended" xlink:role="http://myfchs.com/role/ScheduleOfConvertibleNotesPayableDetails" xlink:title="999024 - Disclosure - SCHEDULE OF CONVERTIBLE NOTES PAYABLE (Details)">
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ConvertibleNotesPayable" xlink:label="loc_us-gaapConvertibleNotesPayable" />
      <link:loc xlink:type="locator" xlink:href="fchs-20260630.xsd#FCHS_ConvertibleNotesPayableGross" xlink:label="loc_FCHSConvertibleNotesPayableGross" />
      <link:calculationArc order="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaapConvertibleNotesPayable" xlink:to="loc_FCHSConvertibleNotesPayableGross" xlink:type="arc" weight="1" />
      <link:loc xlink:type="locator" xlink:href="fchs-20260630.xsd#FCHS_ConvertibleNotesPayableUnamortizedDiscounts" xlink:label="loc_FCHSConvertibleNotesPayableUnamortizedDiscounts" />
      <link:calculationArc order="2" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaapConvertibleNotesPayable" xlink:to="loc_FCHSConvertibleNotesPayableUnamortizedDiscounts" xlink:type="arc" weight="-1" />
    </link:calculationLink>
    <link:calculationLink xlink:type="extended" xlink:role="http://myfchs.com/role/ScheduleOfConvertibleNotesPayableDetailsParenthetical" xlink:title="999025 - Disclosure - SCHEDULE OF CONVERTIBLE NOTES PAYABLE (Details) (Parenthetical)" />
    <link:calculationLink xlink:type="extended" xlink:role="http://myfchs.com/role/NotesPayableDetailsNarrative" xlink:title="999026 - Disclosure - NOTES PAYABLE (Details Narrative)" />
    <link:calculationLink xlink:type="extended" xlink:role="http://myfchs.com/role/ScheduleOfTerminationOfLeaseDetails" xlink:title="999027 - Disclosure - SCHEDULE OF TERMINATION OF THE LEASE (Details)" />
    <link:calculationLink xlink:type="extended" xlink:role="http://myfchs.com/role/ScheduleOfRentInstallmentPaymentsDetails" xlink:title="999028 - Disclosure - SCHEDULE OF RENT INSTALLMENT PAYMENTS (Details)" />
    <link:calculationLink xlink:type="extended" xlink:role="http://myfchs.com/role/LeasesDetailsNarrative" xlink:title="999029 - Disclosure - LEASES (Details Narrative)" />
    <link:calculationLink xlink:type="extended" xlink:role="http://myfchs.com/role/CapitalStockDetailsNarrative" xlink:title="999030 - Disclosure - CAPITAL STOCK (Details Narrative)" />
    <link:calculationLink xlink:type="extended" xlink:role="http://myfchs.com/role/StockOptionsWarrantsAndRestrictedStockUnitsDetailsNarrative" xlink:title="999031 - Disclosure - STOCK OPTIONS, WARRANTS AND RESTRICTED STOCK UNITS (Details Narrative)" />
    <link:calculationLink xlink:type="extended" xlink:role="http://myfchs.com/role/ScheduleOfWarrantsOutstandingDetails" xlink:title="999032 - Disclosure - SCHEDULE OF WARRANTS OUTSTANDING (Details)" />
    <link:calculationLink xlink:type="extended" xlink:role="http://myfchs.com/role/ScheduleOfStockWarrantIssuedDetails" xlink:title="999033 - Disclosure - SCHEDULE OF STOCK WARRANT ISSUED (Details)" />
    <link:calculationLink xlink:type="extended" xlink:role="http://myfchs.com/role/GoingConcernDetailsNarrative" xlink:title="999034 - Disclosure - GOING CONCERN (Details Narrative)" />
</link:linkbase>
