Pro Rata Salary Calculator
Work out the part-time or term-time salary that matches a full-time figure — and the actual take-home pay that comes with it, not just the ratio.
Only working term-time (school staff, for example)? Set weeks a year to 38–39 instead of 52.
Start here
How to use this calculator
Enter the full-time salary for the role, then describe your actual working pattern.
Enter the full-time salary
The salary the job is advertised at, or your contract’s full-time equivalent figure — not what you expect to actually be paid.
Describe your working pattern
Pick your days out of 5, or switch to “Custom hours” and enter your actual weekly hours directly. If you only work part of the year (term-time), change the weeks-a-year figure too.
Read your real pay
The result shows both the pro-rata gross salary and what actually lands in your bank account, with tax, National Insurance, pension and student loan already worked out.
Nearby
Pro rata pay at different days a week
Same full-time salary and settings as above, one day at a time. Your own pattern is highlighted.
| Days a week | % of full-time | Pro rata gross | Take-home |
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The basics
What does “pro rata” actually mean?
Pro rata means “in proportion” — a part-time or term-time salary calculated as a fraction of the full-time equivalent. If a role pays £50,000 full-time and you work 3 days out of a normal 5-day week, your pro-rata salary is 3/5, or 60%, of £50,000: £30,000.
The same principle applies to weeks worked in a year. A term-time role that runs for 39 of the 52 weeks in a year pays 39/52, or 75%, of the full-time salary — even if the hours in each working week are full-time hours. Working part-time hours during a part year (a term-time teaching assistant on 3 days a week, for example) combines both fractions.
Why it matters
Pro rata gross pay is not pro rata take-home pay
Because of how the Personal Allowance and tax bands work, a straightforward percentage of gross pay does not translate into exactly the same percentage of take-home pay. Someone on 60% of a salary usually takes home slightly more than 60% of the full-time net pay, because a smaller income makes proportionally more use of the tax-free Personal Allowance before any tax is due at all.
This calculator runs the pro-rata gross salary through the actual 2026/27 tax and National Insurance rules rather than just applying the same fraction to the take-home figure, which is why the two percentages in the result are not identical.
Questions
Common questions
How do I work out pro rata salary for 3 days a week?
Divide 3 by 5 (a normal full-time week), which gives 0.6, then multiply the full-time salary by 0.6. A £40,000 full-time role becomes £24,000 pro rata for 3 days a week.
Does pro rata apply to term-time only jobs?
Yes. Instead of dividing days worked by 5, divide the weeks you actually work by 52. A role that runs 39 weeks a year pays 39/52 of the full-time salary, roughly 75%, even if you work full-time hours during those weeks.
Is pro rata salary paid monthly or does it change?
Most employers spread a pro-rata annual salary evenly across 12 months, so you are paid the same amount each month even in a term-time role where you do not actually work every month. Check your contract, since a minority of employers pay only for the months actually worked.
Does pro rata affect my tax code or Personal Allowance?
No. Your Personal Allowance and tax code work the same way regardless of whether you are full-time or part-time — they are based on your actual annual income, which for a part-time role is simply lower, not calculated differently.
What is a normal full-time week in the UK?
There is no single legal definition, but 37.5 or 40 hours a week is most common, and the legal maximum average is 48 hours a week under the Working Time Regulations unless you opt out. Check your own contract for the figure that applies to your role.
Where these figures come from. Income tax, National Insurance and student loan rates are taken from gov.uk for the 2026/27 tax year, applied to the pro-rata gross salary calculated from the working pattern entered above. All figures were checked on 23 September 2026.
Income Tax rates and Personal Allowances · Maximum weekly working hours
How we calculate · Editorial policy. This is general information, not tax or employment advice.