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Prorated Salary Calculator

Estimate partial-period pay from an annual salary. Enter the full pay period dates, the days actually worked, and how many pay periods you have per year.

Full pay period
Days worked (partial period)

Enter salary and date ranges to see prorated pay.

Next step: Payroll Calendar Generator

When to use this calculator

Use this calculator whenever an employee did not work a full pay period and pay needs to be scaled to the days actually worked—starting mid-period, leaving mid-period, or taking unpaid leave that spans part of a period.

  • Mid-period new hire

    Calculate first-paycheck pay when someone joins partway through a monthly, semimonthly, or biweekly pay period.

  • Mid-period termination

    Find final pay owed for the days worked when employment ends before a pay period closes.

  • Unpaid leave adjustment

    Estimate reduced pay for a period that included unpaid leave, sabbatical, or an unpaid suspension.

  • Payroll cutoff pairing

    Pair with the Payroll Cutoff Calculator once the prorated amount is confirmed, to find when that partial payment is actually issued.

Inputs

  • Annual salary

    The employee's full annual salary before tax or deductions.

  • Pay periods per year

    12 for monthly, 24 for semimonthly, 26 for biweekly, or 52 for weekly payroll. This sets the base pay for one full period.

  • Full pay period (start and end date)

    The complete pay cycle the partial period falls inside—for example, the 1st through the last day of the month for monthly payroll.

  • Days worked (partial period start and end date)

    The actual start and end dates worked within that full period. These dates must fall inside the full period's range.

How the calculation works

The calculator first divides the annual salary by the number of pay periods per year to get the base pay for one full period.

It then counts inclusive calendar days for both the full period and the partial (worked) period on the UTC calendar, and divides partial-period days by full-period days to get a proration factor.

Prorated pay is the full-period base pay multiplied by that proration factor. The result is gross pay for the partial period only—before tax withholding, benefits, or other deductions.

Worked example

Annual salary: $60,000. Pay periods per year: 12 (monthly). Full pay period: 1 March – 31 March (31 calendar days). Days worked: 15 March – 31 March (17 calendar days).

Base pay for one full monthly period: $60,000 ÷ 12 = $5,000.

Proration factor: 17 ÷ 31 = 0.5484 (about 54.8% of the period).

Prorated pay: $5,000 × 0.5484 ≈ $2,741.94.

Edge cases

  • Partial period outside the full period

    The days-worked range must fall entirely within the full pay period's start and end dates. A range that starts before or ends after the full period is rejected—narrow the full period or correct the worked dates.

  • Variable-length months

    A 30-day full period and a 31-day full period produce different per-day base pay for the same monthly salary, since proration uses inclusive calendar days, not a fixed 30-day assumption.

  • Semimonthly and biweekly periods

    Set pay periods per year to 24 for semimonthly (two periods a month, uneven lengths of 14–16 days) or 26 for biweekly (fixed 14-day periods) so the base pay per period matches the actual schedule.

  • Working every day of the full period

    If the worked range equals the full period exactly, the proration factor is 1.0 and prorated pay equals the full period's base pay—useful as a sanity check before adjusting dates for an actual partial period.

Related Payroll Calculators

The Payroll Cutoff Dates Guide is the primary reference for payroll cutoff windows, processing days, and how weekends and holidays shift a pay date.

The Payroll Cutoff Calculator finds your pay date from a payroll cutoff date and processing days, adjusted off weekends and holidays.

The Pay Period Calculator finds the start and end dates of the current pay period for weekly, biweekly, semimonthly, or monthly schedules.

The Next Payday Calculator chains the Pay Period and Payroll Cutoff logic together to find your next upcoming pay date directly.

The Payroll Calendar Generator builds a multi-period table of pay period ranges and pay dates at once, instead of checking Next Payday repeatedly.

The Payroll Hours Calculator totals a work week or single shift and splits regular from overtime hours using a threshold.

The Overtime Pay Calculator turns hourly rate, regular hours, and overtime hours into gross pay—pair it with the Payroll Hours Calculator when you have raw clock times instead of a pre-split hour total.

The Prorated Salary Calculator estimates partial-period pay from an annual salary when a pay period is only partly worked, such as a mid-period hire or termination.

For date math that a payroll cutoff or pay date depends on—counting weekdays or shifting a date off a weekend—see the Business Days Calculator and Add Business Days To Date Calculator in Date & Business Days.

For employment dates that feed into payroll timing, such as a joining date or last working day, see the HR & Employment category.

FAQ

Does this include taxes or benefits?
No. The result is gross prorated pay before tax withholding, benefits, or employer-specific adjustments.
Why use calendar days instead of working days?
Many salary proration policies use calendar days for simplicity, including weekends in the count. For working-day-based methods, use the Working Days Calculator to count business days separately, then apply your own proration formula.
What if partial days exceed the full period?
The partial range must fit inside the full pay period. Adjust your dates so the worked range does not start before or end after the defined full period.
How is this different from Payroll Hours or Overtime Pay?
This calculator prorates a fixed annual salary by days worked within a pay period. The Payroll Hours and Overtime Pay calculators are for hourly employees, working from actual clocked hours instead of a salary and date range.
Is this my employer's actual proration method?
No. Proration methods vary by employer—some use calendar days, others use working days or a standardized 30-day month. Use this for planning and confirm the exact method with your payroll department.

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