What does pro rata mean for salary?
Pro rata means "in proportion". Your employer takes the full-time salary and pays the share that matches your hours. The law behind this protects part-time staff from being paid a lower hourly rate than a comparable full-time colleague.
How to calculate pro rata salary
Divide your hours by the full-time hours, then multiply the full-time salary by the result. This page works as a part-time salary calculator for the UK and a pro rata salary take home calculator, so you can skip the maths and see what reaches your bank account.
Pro rata salary = full-time salary × (your hours ÷ full-time hours)
So a £36,000 job at 37.5 hours pays £21,600 for 22.5 hours, because 22.5 is 60% of 37.5. After Income Tax and National Insurance that's about £1,589 a month, against £2,453 at full-time hours, so 60% of the hours brings home 65% of the pay. The advert usually shows the full-time figure with "pro rata" beside it, which is why the number in the job listing is rarely the one you'll be paid.
Why your take-home falls by less than your hours
This is the part most calculators leave out. Your personal allowance and National Insurance threshold don't shrink when your hours do, so a lower salary keeps a bigger share of its pay. Going from five days to four cuts gross pay by exactly 20%, but the cut you feel is smaller, and how much smaller depends on what you earn.
| Full-time salary | Gross lost a year | Take-home lost a year | Cut to take-home |
|---|---|---|---|
| £25,000 | £5,000 | £3,600 | 16.7% |
| £35,000 | £7,000 | £5,040 | 17.5% |
| £45,000 | £9,000 | £6,480 | 18.0% |
| £60,000 | £12,000 | £7,278 | 16.0% |
| £80,000 | £16,000 | £9,280 | 16.3% |
| £120,000 | £24,000 | £9,920 | 13.0% |
Look at the last row. Someone on £120,000 who drops a day moves out of the zone where the personal allowance is withdrawn. Their 20% pay cut costs far less than you would expect. If you're weighing up a four-day week, run your own figures above before you decide.
Term-time pay: why 39 ÷ 52 is usually too low
Term-time contracts cause more confusion than any other pattern, and published calculators don't agree on the method. Dividing 39 working weeks by 52 leaves out the paid holiday you earn from working those weeks.
- Worked: 39 weeks
- Paid holiday: 4.7 weeks
- Unpaid: 8.3 weeks
Statutory holiday works out at 5.6 weeks for every 46.4 weeks worked. For a 39-week contract that adds about 4.7 weeks, giving about 43.7 paid weeks. On a £28,000 full-time equivalent that's £23,534 rather than £21,000, a difference of £2,534 a year. Many employers give more holiday than the minimum, so enter your contract's figure in the calculator if you have it.
How does term time only pay work?
You're usually paid for the weeks you work plus the holiday those weeks earn, then that total is spread over 12 equal monthly payments. So you still get paid during the school holidays, even though you aren't working.
To use this as a term-time pay calculator or a pro rata salary calculator for schools, choose Term-time above and enter your weeks. Add your paid holiday weeks if your contract gives them.
If your payslip seems low, ask how many paid weeks your contract uses. That one number explains most term-time pay disputes.
How to work out pro rata holiday
Statutory holiday is 5.6 weeks whatever your hours, so multiply the days you work each week by 5.6. Three days a week gives at least 16.8 days. It's capped at 28 days, and bank holidays can be counted within it.
If your employer gives more than the minimum, scale their figure instead. A full-time allowance of 33 days including bank holidays becomes 19.8 days at three days a week, because 33 × 3 ÷ 5 = 19.8. The Checks tab shows your statutory figure.
Are bank holidays pro rata?
Bank holidays don't have to be given as paid leave, and your employer can count them within your statutory holiday. Many employers add them to the full-time allowance and scale the total, as in the example above. That way, pro rata bank holidays are fair to staff who don't work on Mondays, when many bank holidays fall. Your contract will say which approach applies.
What else should scale with your hours
Bonuses should also be in proportion to your hours, and your rates of sick pay and parental pay should match full-time colleagues'.
Overtime is the common exception. Part-time staff usually aren't entitled to an overtime rate until they've worked more than a full-timer's normal hours. Our overtime calculator shows what those extra hours would be worth.
Pro rata pay questions
What does "£30,000 pro rata" mean in a job advert?
It means £30,000 is the full-time salary, and you'll be paid a share of it based on your hours. Three days in a five-day week would pay £18,000 a year before tax.
What does FTE salary mean?
FTE stands for full-time equivalent. An FTE salary is what the job would pay at full-time hours. So 0.6 FTE means 60% of full-time hours, such as 22.5 hours where the full-time week is 37.5 hours, and your pay is normally 60% of the FTE salary.
Can I use this as an FTE salary calculator?
Yes. Enter the FTE salary as the full-time salary, then your hours. The percentage under your salary is your FTE fraction, so 60.0% means 0.6 FTE.
Does working part-time change my tax code?
Not normally. Your personal allowance is the same whatever hours you work, which is why a lower salary keeps a bigger share of its pay. It can differ if you have a second job or other income.
What is my pro rata hourly rate?
Divide the full-time salary by 52, then by the full-time weekly hours. A £36,000 job at 37.5 hours pays £18.46 an hour. Your hourly rate shouldn't be lower because you're part-time, as it should match a comparable full-time colleague's.
How is pro rata salary worked out for a new employee?
If you start partway through a pay period, your first payment usually covers only the days you've worked. Your contract or payroll team can confirm how they count those days.
How does pro rata salary work when leaving a job?
Your final pay usually covers the days you've worked in that period. It should also include any holiday you've earned but haven't taken.
Does the calculator work for a mid-year start?
Yes. Choose Part-year and enter the months you'll be paid in this tax year. The full personal allowance still applies across those months if you have no other income, which often means less tax each month than a full-year colleague pays.
Why doesn't my payslip match exactly?
Tax codes, pay dates and benefits all change the result. We assume the standard 1257L code and equal monthly pay. See how we calculate for the full list of assumptions.
Sources
Checked on 4 November 2026 against the 2026/27 tax year.
- GOV.UK: Part-time worker rights
- Acas: Part-time workers
- GOV.UK: Holiday entitlement
- GOV.UK: Rates and thresholds for employers 2026 to 2027
- GOV.UK: Income Tax rates and allowances
- GOV.UK: National Minimum Wage and National Living Wage rates
- GOV.UK: Review of the automatic enrolment earnings trigger for 2026/27