Pro-Rata Salary: How Part-Time Pay Is Worked Out
Part-time pay is not a guess and not a negotiation starting point: it is a proportion. This guide shows the one formula behind it.
What is the Pro-Rata Salary Calculator?
Pro rata means in proportion: a part-time salary is the full-time salary scaled down by the fraction of full-time hours actually worked. Enter the full-time annual salary, the full-time weekly hours and the part-time weekly hours, and the tool returns the pro-rata annual salary, the monthly equivalent, the full-time hourly rate (full-time salary divided by full-time hours times 52 weeks) and the part-time fraction. The same principle works with days instead of hours, provided the working day is the same length. Holiday entitlement is usually calculated pro rata too, so part-time staff receive a proportion of the full-time allowance — check your contract for the exact terms.
How to use it
- Enter the full-time annual salary.
- Enter the full-time weekly hours and the part-time weekly hours.
- Click Calculate Pro-Rata Salary to see the annual, monthly and hourly figures.
Worked example
A £30,000 full-time salary at 37.5 hours per week, worked part-time at 22.5 hours, gives £30,000 times 22.5 divided by 37.5, which is £18,000 per year, or £1,500 per month, at 60% of full-time hours.
What is the pro-rata salary for £30,000 full-time at 22.5 of 37.5 hours?
Multiply £30,000 by 22.5 and divide by 37.5 to get £18,000 per year, or £1,500 per month. The full-time hourly rate behind it is £30,000 divided by 37.5 times 52, which is £15.38 per hour.
Frequently asked questions
What does pro rata mean?
In proportion. A part-time salary is scaled down from the full-time salary in proportion to the hours or days actually worked.
What if I work fewer days, not fewer hours?
Use the same principle with days: full-time salary times part-time days divided by full-time days, provided the working day is the same length.
Does pro rata affect holiday entitlement?
Yes, holiday is usually also calculated pro rata, so part-time staff receive a proportion of the full-time holiday allowance. Check your contract for the exact terms.