ProRata CalculatePro Rata Calculator — Work Out Part-Time Pay Properly
Work out what a part-time job actually pays. Enter the full-time salary and the hours you will work, and this calculator shows your pro rata pay — per year, month and week — plus a UK take-home estimate for 2026/27.
Pro Rata Salary Calculator
Type the full-time figures from the advert or contract, then your own pattern. The answer updates as you type.
What lands in your bank account?
Gross pay is only half the story. Add your tax region and any pension contribution and this estimate applies 2026/27 Income Tax and National Insurance to the pro rata figure above. Pension is treated as salary sacrifice, so it comes off before tax and National Insurance are worked out.
Estimated take-home: — a year
| Full-time version | Your pattern | |
|---|---|---|
| Gross pay | — | — |
| Income Tax | — | — |
| National Insurance | — | — |
| Take-home | — | — |
Breakdown of your pattern — gross —, pension —, tax —, National Insurance —, leaving — a month and — a week. Student loans, benefits in kind and other deductions are not included.
Pro rata, in plain English
Pro rata is Latin, and it simply means in proportion. When a job is paid pro rata, everything is scaled by one fraction: your hours divided by the full-time hours. Work 60% of the week and you receive 60% of the salary, 60% of the leave and 60% of most other entitlements — but exactly 100% of the hourly rate. That last point is the test of a fair offer, and it is why this site is also used as a pro rata pay calculator and a calculator pro rata for checking adverts before an interview: if the hourly rate in the offer is lower than the full-time hourly rate, the offer is not genuinely pro rata.
People arrive here under all sorts of spellings — pro rata calculator uk, pro rata calc, prorata calculator — because employers write the phrase a dozen different ways in adverts. The sum underneath never changes. Find your fraction first, then apply it to each figure you care about: pay on this page, leave on the holiday calculator, and term-time weeks on the teacher calculator.
Three patterns, one fraction
By hours suits most office, retail and professional roles, where contracts state hours per week. By days suits workplaces that roster whole days, and it is the tab to use when an advert says “3 days per week” without mentioning hours. Term time adds a second step: after the hours fraction, pay is scaled again by paid weeks out of 52, because term-time staff are paid for term weeks plus holiday weeks, not for the whole year. Use the mode switch inside the calculator above, or open the dedicated term-time calculator for the full explanation.
School-hours staff often need both steps at once — fewer hours and fewer weeks — and that combination is exactly where offer letters most often go wrong, usually by applying one fraction and forgetting the other. Work through each step separately and the error becomes easy to spot.
Worked examples, checked by hand
| Situation | The fraction | Annual pay | Monthly |
|---|---|---|---|
| Administrator, £33,500 full time, 22.5 of 37.5 hours | 22.5 ÷ 37.5 = 0.60 | £20,100.00 | £1,675.00 |
| Receptionist, £27,750 full time, 3 of 5 days | 3 ÷ 5 = 0.60 | £16,650.00 | £1,387.50 |
| Support worker, £31,200 full time, 30 of 40 hours | 30 ÷ 40 = 0.75 | £23,400.00 | £1,950.00 |
| Bookkeeper, £42,800 full time, 16 of 40 hours | 16 ÷ 40 = 0.40 | £17,120.00 | £1,426.67 |
Try any row in the calculator above and you will land on the same figures. Then change one number — the hours, say — and watch the monthly figure move while the hourly rate stays put. That behaviour, totals moving and rate standing still, is the clearest sign the arithmetic is behaving as a pro rata salary should.
Questions people ask
It means the salary printed is the full-time amount, and you receive the slice of it that matches your hours. A post advertised at £33,500 pro rata, worked at 22.5 hours where full time is 37.5, pays £20,100 a year before deductions. Our longer explainer, what does pro rata mean, unpacks the wording in full.
The pro rata maths works anywhere, because it is only a proportion. The take-home estimates underneath are UK-specific: they apply 2026/27 Income Tax, National Insurance and the Scottish bands where you choose Scotland. That is why people searching for a pro rata calculator UK, a pro rata calc or a prorata calculator all land on the same arithmetic — the difference is only the deductions afterwards.
Take the hours in the advert, divide by the full-time hours for that workplace, and multiply £28,000 by the answer. At 20 hours out of 37.5, that is £28,000 × 0.5333 = £14,933.33 a year. If the advert gives days instead of hours, divide days by days — the method does not change.
No. A fair pro rata arrangement keeps the hourly rate identical and reduces only the total. If the hourly rate falls when the hours fall, you are being offered less than pro rata, and it is worth asking payroll to show their working before you sign anything.
Nothing is stored and nothing leaves your browser. The figures are worked out on your own device the moment you type them, and they vanish when you close the tab. The share button builds a link containing your figures only if you choose to press it.
There is none in the maths — “prorated” is simply the American spelling of the same idea, and a salary prorated calculator does the identical sum. UK contracts and adverts almost always use “pro rata”, which is why this site uses that wording throughout.
Rates used: UK tax year 2026/27 · Last reviewed: October 2026. Calculations run in your browser — nothing you type is sent anywhere or stored by us.