Salary Proration Calculator
Salary proration works out the pay due when an employee works only part of a pay period, for example when they start or leave partway through, change their rate mid-cycle, or take unpaid leave. This calculator applies the standard method: prorated pay equals the annual salary multiplied by the number of days worked, divided by the number of days in the period. By default the period is a full calendar year of 365 days, so entering days worked since a start date gives the salary earned so far. Enter the annual salary, the days actually worked, and the days in the period, and the tool returns the prorated amount and the daily rate it implies. This is useful for new hires, departures, and any situation where a full period's salary would overstate what is owed. Because employers use different conventions, such as calendar days, working days, or a 360-day year, the days-in-period figure is kept editable so you can match your payroll method exactly. The US Internal Revenue Service governs the income tax withheld from the resulting wages. Every figure here is computed deterministically from the formula shown in full below, with a worked example that reconciles exactly to the calculator so you can follow each step.
Prorated pay scales salary to the days worked: prorated pay = annual salary times days worked / days in period. A $60,000 salary for 90 of 365 days is $14,794.52.
Salary Proration formula
Prorated pay = Annual salary x (days worked / days in period)
Annual salary = full-period salary
days worked = days actually worked in the period
days in period = total days in the full period (often 365)
The daily rate is the annual salary divided by days in the period; multiplying it by days worked gives the prorated pay.
Worked example
Find the prorated pay for 90 days worked on a 60,000 annual salary across a 365-day year.
- Daily rate: 60,000 / 365 = 164.3836
- Multiply by days worked: 164.3836 x 90 = 14,794.52
- Prorated pay = 14,794.52
These are the calculator's default inputs, so the result above matches the widget exactly.
Salary Proration Calculator: frequently asked questions
When is salary prorated?
Salary is prorated whenever an employee works only part of a period, such as starting or leaving mid-month, changing pay rate, or taking unpaid leave. Proration ensures pay reflects the actual time worked.
Should I use calendar days or working days?
Either can be correct depending on your employer's policy. Calendar-day proration divides by total days; working-day proration divides by scheduled work days. Set the days-in-period input to match your payroll method.
How do I prorate a monthly salary?
Set the annual salary to twelve times the monthly amount, or set days in period to the days in that month and the annual salary to the monthly figure scaled to a year. The simplest approach is to use the period that matches your input convention.
Does proration change tax withholding?
Prorated wages are taxed as ordinary income. The dollar amount is smaller, so the tax withheld for that period is correspondingly smaller, but the rules are unchanged.
What is the salary proration formula?
Prorated pay equals the annual salary times days worked divided by days in the period. For 60,000 over 90 of 365 days, that is 14,794.52.
Official sources
- US federal payroll, withholding and reimbursement guidance: US Internal Revenue Service (IRS). As at 25 June 2026.
Reviewed by the CalculatorHub team, edited by James Graham, 25 June 2026. See our methodology. This is general information, not financial, tax, legal or investment advice.