Pro Rata Salary Calculator

A pro rata salary is a full-time salary reduced to match the hours you work, so 22.5 hours of a 37.5-hour job pays 60% of the full-time figure. The same sum gives a pro rata wage for an hourly or weekly job.

"Pro rata" is Latin for "in proportion". On a job advert it means the salary shown is the pay for a full-time week, and what you are paid is that salary scaled down to the hours you actually work. It is a figure before tax.

So an advert at £30,000 pro rata, for 22.5 hours of a 37.5-hour week, pays £18,000 a year: 60% of the full-time figure, or £1,500 a month before tax. "FTE" (full-time equivalent) means the same full-time figure.

Some adverts, especially in schools and the NHS, give two numbers: the full-time salary and an "actual salary". The actual salary has already been scaled to the hours, so it is what you would be paid before tax. The calculator handles both: you choose which one you are typing in.

You do not need to work anything out first. Type the figures as they are printed on your advert, contract or rota, and the page does the converting and shows its working. Every box is already filled with a common value, so you only change what is different for you.

1. The pay. Type the figure and say how it is given (a year, a month or an hour) and whether it is the full-time pay or what you will actually be paid. An hourly rate is the same either way.
2. The full-time week. Usually 37.5 hours over 5 days. The advert or contract will say if it is different.
3. Your week. Give it as hours a week, days a week, or the hours you work on each day. The last way is for rotas where one day is long and another short.
4. Term-time only? Tick the box and the page asks for the weeks you work (or school days) and your paid holiday, in days or weeks, both filled with the common school contract.
5. Take-home details. Folded away but already filled in: where you pay tax, how often you are paid, a student loan, and a 5% workplace pension. Open it to match your payslip.

You get your pay a year, a month and each payday, your take-home pay, your holiday, and how it all compares with full time.

To calculate a pro rata salary, or the part-time salary for a full-time job, divide your hours by the full-time hours and multiply by the full-time pay. Three examples:

Fewer hours. 22.5 of 37.5 hours is 60%. On £30,000 that is £18,000 a year. Your hourly rate does not change: it is £15.34, the same as a full-time colleague's.

A four-day week. Four days out of five is 80%. On £35,000 that is £28,000 a year. In take-home terms (England, Wales or Northern Ireland, no pension or student loan) it moves from £2,393 to £1,973 a month.

Working back from an actual salary. If the advert says £18,000 for 22.5 of 37.5 hours, that is 60% of a full-time £30,000. Divide the actual salary by your share of full time to get the full-time figure.

Many term-time staff are paid in 12 equal monthly amounts (your contract says), so pay does not stop when the school closes. The yearly pay covers the weeks you work and your paid holiday, bank holidays included. In words: add your weeks worked to your paid holiday weeks, divide by the weeks in a year (52.14), and apply that to the full-time salary for your hours.

This is the pattern for term-time only roles such as school support staff and teaching assistants, paid for the weeks or school days worked plus paid holiday.

Here is an example. £25,000 full time, 32.5 of 37 hours a week, 39 weeks worked and 33 days (6.6 weeks) of paid holiday. That is 45.6 paid weeks, so the pay is £19,204 a year, or £1,600 a month before tax. A calculation that forgets the holiday weeks gives £16,424, which is £2,780 a year too low.

On the holiday itself: the law counts workers whose pay stops for a week or more at a time as "part-year workers". For leave years from 1 April 2024, their paid holiday builds up with the time they work, commonly worked out as 12.07% (5.6 weeks of leave for every 46.4 weeks worked). For 39 weeks that is about 4.7 weeks. Many school contracts give more: 33 days including bank holidays is common in local government. What counts is your own contract, so use the figures printed on it.

Pro rata annual leave works the same way as pro rata pay: your holiday is the full-time entitlement scaled to the hours you work.

Most workers get 5.6 weeks of paid holiday a year, up to a limit of 28 days. Part-time workers get the same 5.6 weeks, which comes to fewer days. For three days a week that is 3 × 5.6 = 16.8 days. On a 37.5-hour full-time week that is 126 hours.

Bank holidays do not have to be paid leave, but an employer can count them as part of the 5.6 weeks. That is why contracts are written both ways: "25 days plus bank holidays" or "33 days including bank holidays". The calculator asks which, and fills in the usual number of bank holidays: 8 in England and Wales, 9 in Scotland and 10 in Northern Ireland.

If your days are different lengths, or you never work a particular weekday, count holiday in hours rather than days: it is the fairer measure, and it is what the calculator shows first.

The personal allowance, the National Insurance threshold and the student loan threshold are fixed amounts, so they take a smaller share of a smaller salary. On £30,000, working 60% of the hours earns 60% of the full-time pay but keeps 65.6% of the full-time take-home (£1,373 against £2,093 a month, with no pension or student loan).

It works in the other direction too: one more hour a week would add about £48 a month to that take-home pay, and the calculator shows this figure for your own numbers. A workplace pension is a separate point: below £10,000 a year an employer does not have to enrol you automatically, though you can ask to join.

Part-time workers have the right not to be treated less favourably than comparable full-time colleagues. That covers the hourly rate, holiday and pension, all applied in proportion to the hours worked, so a part-time hourly rate matches the full-time one.

The calculator also compares your hourly rate with the minimum wage for your age. From April 2026 the National Living Wage for workers aged 21 and over is £12.71 an hour. If the figure you type works out below it, the page says so. Term-time staff are paid for their holiday weeks too, so the page also shows what each hour you actually work is worth.

• Dividing by 52 when the contract uses 52.14 (365 days ÷ 7). The calculator lets you pick either.
• Leaving the paid holiday weeks out of term-time pay, which makes it too low.
• Counting days when your days are different lengths. Use hours each day instead.
• Treating a pro rata salary as pay after tax. It is before tax.
• Scaling an "actual salary" down a second time.
• Copying a holiday figure from the full-time contract without scaling it to your hours.

It is built for people employed through PAYE, with one job. It assumes the standard tax code and works out tax, National Insurance, student loan and pension as payroll does each payday. It does not include overtime, bonuses, benefits in kind, a second job, the self-employed, or a tax code that your employer or HMRC has changed. If your payslip differs by a few pounds, a different tax code or pension arrangement is the usual reason.

Everything is an estimate from the figures you type in. Nothing you type leaves your device. Check anything that affects a decision against your contract or with your employer's payroll team.