Pro Rata Salary Calculator (2026/27)
Turn a full-time salary into what you will actually be paid for your hours — including term-time-only roles — with the take-home pay after tax and National Insurance, not just the gross figure.
Your pro-rata pay
An estimate for guidance only, not financial advice. Assumes the full-time salary is the figure your employer pro-rates from, and that pay is spread evenly across the year. Overtime, unsocial-hours enhancements and salary sacrifice are not included here — the full take-home calculator covers those.
How a pro-rata salary is worked out
Pro rata means "in proportion". A job advertised at £40,000 pro rata does not pay £40,000 for part-time hours — it pays the share of it that matches the hours you work:
Your hours ÷ full-time hours × full-time salary
So 30 hours against a 37.5-hour week is 80% of full time, and £40,000 becomes £32,000.
Full-time hours vary by employer and sector — 37.5 is common in the NHS and much of the public sector, while 35, 40 and 42 hours all appear elsewhere. The fraction depends on that number, so it is worth checking rather than assuming: the same 30 hours is 75% of a 40-hour week but 85.7% of a 35-hour one.
Pro rata pay for common part-time hours
| Full-time salary | 30 hrs 80% | 22.5 hrs 60% | 18.75 hrs 50% | 15 hrs 40% |
|---|---|---|---|---|
| £25,000 | £20,000 £1,493/mo net | £15,000 £1,193/mo net | £12,500 £1,042/mo net | £10,000 £833/mo net |
| £30,000 | £24,000 £1,733/mo net | £18,000 £1,373/mo net | £15,000 £1,193/mo net | £12,000 £1,000/mo net |
| £35,000 | £28,000 £1,973/mo net | £21,000 £1,553/mo net | £17,500 £1,343/mo net | £14,000 £1,133/mo net |
| £40,000 | £32,000 £2,213/mo net | £24,000 £1,733/mo net | £20,000 £1,493/mo net | £16,000 £1,253/mo net |
| £50,000 | £40,000 £2,693/mo net | £30,000 £2,093/mo net | £25,000 £1,793/mo net | £20,000 £1,493/mo net |
| £60,000 | £48,000 £3,173/mo net | £36,000 £2,453/mo net | £30,000 £2,093/mo net | £24,000 £1,733/mo net |
Pro-rata gross, with monthly take-home underneath, against a 37.5-hour full-time week for 2026/27.
For the band-by-band Income Tax behind any of these figures, use the full take-home pay calculator, or read how UK Income Tax works.
Why part-time take-home isn't proportional to your hours
This is the part most pro-rata calculators leave out. Halving your hours halves your gross pay, but it does not halve your take-home — you keep a larger share of what you earn.
The reason is that the two thresholds doing the most work on a payslip are fixed per person and are not pro-rated with the job. Your Personal Allowance is £12,570 whether you work five days a week or one, and National Insurance only starts above £12,570 of earnings. Drop your hours and a bigger proportion of your pay sits underneath both.
| Hours a week | Of full time | Gross | Take-home | Share of gross kept | vs. scaling take-home |
|---|---|---|---|---|---|
| 37.5 hrs | 100% | £40,000 | £32,320 | 80.8% | — |
| 30 hrs | 80% | £32,000 | £26,560 | 83% | +£704 |
| 22.5 hrs | 60% | £24,000 | £20,800 | 86.7% | +£1,408 |
| 18.75 hrs | 50% | £20,000 | £17,920 | 89.6% | +£1,760 |
| 15 hrs | 40% | £16,000 | £15,040 | 94% | +£2,112 |
| 7.5 hrs | 20% | £8,000 | £8,000 | 100% | +£1,536 |
On a £40,000 full-time salary for 2026/27. The last column is how much more you take home than you would if take-home simply scaled with hours.
At half hours the gap is £1,760 a year. At the smallest pattern shown, gross pay lands under the Personal Allowance and the NI threshold entirely, so the whole amount is kept — an effective deduction rate of nothing at all. It is the same reason a student loan repayment can stop completely when hours are cut: it applies only above a threshold that does not move.
Term-time-only salary
Term-time staff — teaching assistants, school administrators, catering and site teams — are pro-rated twice: once on hours against a full-time week, and again on paid weeks against the 52.14 weeks in a year (365 ÷ 7). That second step is why term-time pay comes out lower than the hours alone suggest.
Paid weeks normally means the weeks you actually work plus your holiday entitlement. GOV.UK puts statutory paid holiday at 5.6 weeks a year for almost all workers, which is the default used above.
A worked example: £23,500 full-time equivalent, 30 hours against 37.5, working 38 weeks plus 5.6 weeks' holiday — that is 43.6 paid weeks, or 83.6% of the year. Combined with 80% of full-time hours, the salary is 66.9% of £23,500 = £15,720, or about £1,236 a month after tax and National Insurance.
That figure is normally averaged and paid in twelve equal instalments so the payslip does not stop over the holidays. Employers genuinely differ in which weeks they count and whether they use 52, 52.14 or 52.18 as the divisor, so treat this as a check on your contract rather than a replacement for it.
Pro rata salary FAQ
What does pro rata mean on a salary?
It means the advertised figure is the full-time salary, and you will be paid the share of it that matches your hours. A £40,000 job advertised "pro rata" pays £32,000 if you work 30 hours against a 37.5-hour full-time week. The rate for the job does not change — only the number of hours you are paid for.
How do I calculate a pro rata salary?
Divide your hours by the full-time hours for the role, then multiply the full-time salary by that fraction. For 30 hours against 37.5, that is 30 ÷ 37.5 = 80%, so £40,000 becomes £32,000. Term-time staff are pro-rated a second time, on paid weeks rather than hours.
Do part-time workers keep more of their pay?
As a share of gross, yes. The Personal Allowance (£12,570) and the National Insurance threshold (£12,570) are fixed per person and are not reduced with your hours. On a £40,000 full-time salary you keep 80.8% of gross; at half those hours you keep 89.6%. You still earn less overall — you just lose a smaller proportion of it to tax and NI.
How is term-time-only pay calculated?
Twice over: once for your hours against a full-time week, and once for your paid weeks against the 52.14 weeks in a year. Paid weeks normally means the weeks you work plus your holiday entitlement. The result is usually averaged and paid in twelve equal monthly instalments, so your payslip does not stop over the school holidays. Employers differ in exactly which weeks they count, so check your contract against the figure here.
Do part-time workers get holiday pay pro rata?
Yes. GOV.UK states almost all workers are legally entitled to 5.6 weeks' paid holiday a year, and part-timers get the same 5.6 weeks — it just amounts to fewer days. Someone working 3 days a week is entitled to at least 16.8 days (3 × 5.6). Statutory entitlement is capped at 28 days, so a 6-day-a-week worker still gets 28.
Is a pro rata salary the same as part-time?
Not quite. Pro rata describes how the pay is worked out, not the contract. It is used for part-time hours, for term-time-only roles, and for anyone who joins or leaves partway through a year — in that last case the salary is pro-rated across the months actually worked rather than across hours.
Does a pension or student loan change when I go part-time?
Both are percentages of actual pay, so they fall with your salary. A student loan can stop entirely: repayments only apply above your plan's threshold, so dropping below it means nothing is deducted. Pension contributions continue as a percentage of what you earn, though auto-enrolment has its own earnings trigger.