> ## Documentation Index > Fetch the complete documentation index at: https://docs.flowpayroll.ai/llms.txt > Use this file to discover all available pages before exploring further. # Calculate the salary lines for a pay period > Runs the pro-rata calculation for one employee and pay period with no side effects, using the employee's salary history and working pattern exactly as a pay run does. Supply `year` and `period` to get the line item ids the pay run would receive. Supply `statutoryLines` to preview the salary adjustment and any top-up the employee's statutory leave policy produces for them; each result line carries its `kind`. ## OpenAPI ````yaml /api-reference/specs/salary.json post /employees/{employeeId}/calculate openapi: 3.0.1 info: title: Salary Service description: >- Salary module API for FlowPayroll: organisation and employee calculation-method configuration, statutory leave policies, and a side-effect-free pro-rata calculation. Enums may gain values and objects may gain properties without a new version, so a client should ignore properties it does not know and treat an enum value it does not recognise as unsupported. version: v1 servers: - url: https://api.sandbox.flowpayroll.ai/v1/salary security: - X-Auth-Token: [] X-Org-Id: [] paths: /employees/{employeeId}/calculate: post: tags: - Salary lines summary: Calculate the salary lines for a pay period description: >- Runs the pro-rata calculation for one employee and pay period with no side effects, using the employee's salary history and working pattern exactly as a pay run does. Supply `year` and `period` to get the line item ids the pay run would receive. Supply `statutoryLines` to preview the salary adjustment and any top-up the employee's statutory leave policy produces for them; each result line carries its `kind`. operationId: CalculateSalary parameters: - name: employeeId in: path required: true schema: type: string requestBody: content: application/json: schema: $ref: '#/components/schemas/CalculateSalaryRequest' responses: '200': description: OK content: application/json: schema: $ref: '#/components/schemas/SalaryCalculationResponseResponseBody' '400': description: Bad Request content: application/json: schema: $ref: '#/components/schemas/ObjectResponseBody' '404': description: Not Found content: application/json: schema: $ref: '#/components/schemas/ObjectResponseBody' components: schemas: CalculateSalaryRequest: required: - frequency - payrollConfigId - periodEndDate - periodStartDate type: object properties: payrollConfigId: minLength: 1 type: string description: The payroll configuration the pay period belongs to. periodStartDate: minLength: 1 type: string description: First day of the pay period, YYYY-MM-DD. periodEndDate: minLength: 1 type: string description: Last day of the pay period, YYYY-MM-DD. frequency: minLength: 1 type: string description: >- Pay frequency: Weekly, Fortnightly, FourWeekly, Monthly, Quarterly, BiAnnually or Annual. year: type: integer description: >- Tax year of the pay run. Optional; with `period` it makes the returned line item ids match the ones the pay run receives. format: int32 nullable: true period: type: integer description: Period number of the pay run. Optional; see `year`. format: int32 nullable: true statutoryLines: type: array items: $ref: '#/components/schemas/CalculateStatutoryLineRequest' description: >- Statutory pay lines to treat as if they were on the payslip, so the salary adjustment and any top-up can be previewed. Optional. nullable: true additionalProperties: false description: >- Runs the salary calculation for one employee and one pay period without side effects. SalaryCalculationResponseResponseBody: type: object properties: message: $ref: '#/components/schemas/MessageWithTokenResponse' content: $ref: '#/components/schemas/SalaryCalculationResponseContentResponse' validationIssues: type: array items: $ref: '#/components/schemas/ValidationIssue' nullable: true additionalProperties: false ObjectResponseBody: type: object properties: message: $ref: '#/components/schemas/MessageWithTokenResponse' content: $ref: '#/components/schemas/ObjectContentResponse' validationIssues: type: array items: $ref: '#/components/schemas/ValidationIssue' nullable: true additionalProperties: false CalculateStatutoryLineRequest: type: object properties: statutoryType: type: string description: The statutory type name, e.g. `StatutoryMaternityPay`. nullable: true units: type: number description: Days paid (qualifying days for sick pay, calendar days otherwise). format: double unitName: type: string description: '`Day` or `Fixed`.' nullable: true amount: type: number description: The line's amount. format: double id: type: string description: The line's id; seeds the adjustment and top-up ids. Optional here. nullable: true from: type: string description: First day the line pays for inside the period, YYYY-MM-DD. nullable: true to: type: string description: Last day the line pays for, YYYY-MM-DD. nullable: true leaveStart: type: string description: >- First day of the statutory payment, YYYY-MM-DD; top-up tiers count from it. nullable: true periodAmount: type: number description: >- Statutory pay for this period's days, when the line also covers earlier periods. format: double nullable: true additionalProperties: false description: >- A statutory pay line in the shape the statutory service posts it: its type, units and amount, and, when known, the days it pays for inside the period, the statutory payment's start date and the amount that pays for this period's days. MessageWithTokenResponse: type: object properties: text: type: string token: type: string tokenArguments: type: array items: $ref: '#/components/schemas/ValidationIssueArgument' nullable: true additionalProperties: false SalaryCalculationResponseContentResponse: type: object properties: data: $ref: '#/components/schemas/SalaryCalculationResponse' metadata: $ref: '#/components/schemas/ContentMetadataResponse' additionalProperties: false ValidationIssue: type: object properties: field: type: string reason: type: string reasonToken: type: string reasonTokenArguments: type: array items: $ref: '#/components/schemas/ValidationIssueArgument' nullable: true additionalProperties: false ObjectContentResponse: type: object properties: data: nullable: true metadata: $ref: '#/components/schemas/ContentMetadataResponse' additionalProperties: false ValidationIssueArgument: type: object properties: name: type: string value: nullable: true additionalProperties: false SalaryCalculationResponse: type: object properties: calculationMethod: enum: - CalendarDays - WorkingDays type: string description: The method the calculation used. source: enum: - Default - Organisation - Employee type: string description: >- Where that method came from: `Employee`, `Organisation` or `Default`. lines: type: array items: $ref: '#/components/schemas/SalaryCalculationLine' description: >- The salary lines, then for each statutory payment its adjustments and top-up. additionalProperties: false ContentMetadataResponse: type: object properties: dateFormat: type: string dateTimeFormat: type: string paginationToken: type: string nullable: true additionalProperties: false SalaryCalculationLine: type: object properties: lineItemId: type: string description: >- The id the line would be posted under, derived from the employee, pay run, period and segment; null when the request carried no `year` and `period`. nullable: true description: type: string description: The line's description as it appears on the payslip. unitName: type: string description: >- What `units` counts: `Month`, `Week` or `Year` for a full period, `Day` for a part period or an adjustment, `Fixed` for a top-up. units: type: number description: How many of `unitName`. format: double payRate: type: number description: The rate per unit, to 4 decimal places. format: double amount: type: number description: >- The line's amount: units × payRate, rounded to the penny. Always positive; an adjustment is a deduction because of its pay element. format: double annualSalary: type: number description: The annual salary in force for the segment. format: double effectiveFrom: type: string description: The date that salary version took effect, YYYY-MM-DD. segmentStart: type: string description: >- First day the line pays for (or, for an adjustment, takes back), YYYY-MM-DD. segmentEnd: type: string description: Last day the line covers, YYYY-MM-DD. calculationMethod: enum: - CalendarDays - WorkingDays type: string description: How the days were counted. divisor: type: integer description: >- Qualifying days in the tax year containing the segment's first day, for a part period; null for a full period. format: int32 nullable: true kind: enum: - Salary - StatutoryAbsenceAdjustment - StatutoryTopUp type: string description: >- `Salary`, `StatutoryAbsenceAdjustment` (the salary for days on statutory leave, taken back) or `StatutoryTopUp` (contractual pay on top of statutory pay). payElementId: type: string description: The pay element the line is posted against, e.g. `internal_salary`. nullable: true statutoryType: enum: - StatutorySickPay - StatutoryMaternityPay - StatutoryPaternityPay - StatutoryAdoptionPay - StatutorySharedParentalPay - StatutoryParentalBereavementPay - StatutoryNeoNatalCarePay type: string description: On an adjustment or top-up, the statutory payment it responds to. nullable: true additionalProperties: false description: One pay-run line the calculation would produce. securitySchemes: X-Auth-Token: type: apiKey description: FlowPayroll JWT (raw token, no Bearer prefix) name: X-Auth-Token in: header X-Org-Id: type: apiKey description: >- Organisation to scope the request to. Required when the principal can access more than one organisation; optional for single-organisation principals (the authorizer resolves it automatically). name: X-Org-Id in: header ```` This documentation is built and hosted on [Mintlify](https://mintlify.com), a developer documentation platform.