Pro-Rata Salary Calculator 2026/27
By Omair SaoLast reviewed — income tax, National Insurance and student loan thresholds for the 2026/27 tax year. See how we check our figures.
Enter the full-time salary from the job advert and the hours or days you will actually work. The calculator gives your pro-rata salary and your monthly take-home pay after income tax and National Insurance. It also shows your hourly rate and holiday entitlement, and it handles term-time only contracts.
Pro-rata salary quick reference
Annual pro-rata pay for common full-time salaries on a five-day week, with monthly take-home pay in brackets (standard tax code, no pension or student loan).
| Full-time salary | 2 days a week | 3 days a week | 4 days a week |
|---|---|---|---|
| £25,000 | £10,000£833 a month take-home | £15,000£1,193 a month take-home | £20,000£1,493 a month take-home |
| £30,000 | £12,000£1,000 a month take-home | £18,000£1,373 a month take-home | £24,000£1,733 a month take-home |
| £35,000 | £14,000£1,133 a month take-home | £21,000£1,553 a month take-home | £28,000£1,973 a month take-home |
| £40,000 | £16,000£1,253 a month take-home | £24,000£1,733 a month take-home | £32,000£2,213 a month take-home |
| £50,000 | £20,000£1,493 a month take-home | £30,000£2,093 a month take-home | £40,000£2,693 a month take-home |
Take-home figures use the 2026/27 Personal Allowance of £12,570, 20% basic-rate tax and 8% employee National Insurance from GOV.UK, Income Tax rates and GOV.UK, National Insurance rates.
Your rights as a part-time worker
- The same hourly rate as a comparable full-time colleague, and the same overtime rate once you pass full-time hours.
- Holiday, sick pay, bonuses, pension contributions and training on a pro-rata basis, never less favourable terms simply because you work part-time.
- The right to ask for a written explanation within 21 days if you think you are being treated less favourably.
- The 2026/27 National Living Wage of £12.71 an hour for workers aged 21 and over applies to every hour you work, however few.
- Part-time earnings often qualify for Universal Credit; the taper takes 55p of every £1 earned above any work allowance, so check before turning down hours.
Who this pro-rata salary calculator is for
- Anyone offered a part-time job advertised with a full-time equivalent (FTE) salary who wants to know what it really pays for their hours.
- Employees cutting their hours after parental leave or for caring responsibilities, who need to see the effect on monthly take-home pay before they decide.
- Term-time only staff, such as teaching assistants and school administrators, whose pay is scaled for the weeks they work as well as the hours.
- Job sharers and people working compressed or four-day weeks who want to check their contract against the full-time rate.
- Employers and HR teams working out a fair salary and holiday allowance for a part-time hire.
How the pro-rata salary calculator works
- 1
Scale the salary by hours or days
A pro-rata salary is the full-time salary multiplied by your share of full-time hours: £35,000 a year for a 37.5-hour week is £21,000 for 22.5 hours (22.5 ÷ 37.5 = 60%). Working by days gives the same answer: three days out of five is 60%. Enter whichever your contract uses.
- 2
Adjust for paid weeks if you are term-time only
Term-time contracts pay for the weeks worked plus pro-rata holiday, usually 44 to 47 weeks out of 52, and the money is spread over 12 equal monthly payments. Enter the paid weeks from your contract and the calculator scales the salary a second time.
- 3
Work out take-home pay
Tax is charged on annual income, so a part-time salary often falls into a lower band than the full-time figure. The calculator applies the 2026/27 Personal Allowance of £12,570, income tax at 20%, 40% and 45% (or the Scottish rates), employee National Insurance at 8% above £12,570, student loan repayments and any pension contribution, using the same functions as our take-home pay calculator.
- 4
Pro-rate the holiday too
Part-time workers get the same holiday as full-timers in proportion to their working week: 5.6 weeks by law, so 16.8 days for a three-day week. If your employer offers more than the 28-day statutory minimum, enter their full-time figure and the calculator scales it. Holiday is scaled by hours or days, never by term-time weeks.
Worked examples
£35,000 FTE role, three days a week
An office job is advertised at £35,000 full-time equivalent for five days a week. The applicant wants to work Monday to Wednesday.
| Share of full-time3 ÷ 5 days | 60% |
| Pro-rata salary£35,000 × 60% | £21,000 |
| Income tax(£21,000 − £12,570) × 20% | £1,686 |
| Employee National Insurance(£21,000 − £12,570) × 8% | £674.40 |
| Annual take-home pay | £18,639.60 |
| Monthly take-home pay | £1,553.30 |
| Holiday entitlement28 days × 3 ÷ 5 | 16.8 days |
Result: The three-day role pays £1,553 a month after tax. A full-time colleague on £35,000 keeps £2,393 a month, so the two days not worked cost £840 a month in take-home pay, less than 40% of the full-time figure because more of the part-time pay sits inside the tax-free allowance.
£42,000 FTE, 22.5 hours out of 37.5
A nurse returning from maternity leave moves from 37.5 hours to 22.5 hours a week on a £42,000 full-time salary.
| Share of full-time22.5 ÷ 37.5 hours | 60% |
| Pro-rata salary | £25,200 |
| Hourly rate£42,000 ÷ (37.5 × 52) | £21.54 |
| Income tax | £2,526 |
| Employee National Insurance | £1,010.40 |
| Annual take-home pay | £21,663.60 |
| Monthly take-home pay | £1,805.30 |
Result: Dropping 15 hours a week reduces take-home pay from £2,813 to £1,805 a month. Pension contributions and any Universal Credit entitlement, which the calculator does not include, would change the final figure.
Term-time only teaching assistant
A school advertises a teaching assistant post at £28,000 FTE for 30 hours a week, term-time only, paid for 44 weeks a year.
| Share of full-time hours30 ÷ 37.5 | 80% |
| Paid weeks | 44 of 52 |
| Pro-rata salary£28,000 × 80% × 44 ÷ 52 | £18,953.85 |
| Income tax | £1,276.77 |
| Employee National Insurance | £510.71 |
| Annual take-home pay | £17,166.37 |
| Monthly take-home payPaid in 12 equal instalments | £1,430.53 |
Result: The advertised £28,000 becomes £18,954 a year, or £1,431 a month after tax, once both the shorter week and the term-time weeks are applied. Always ask which weeks figure the employer uses; 44, 45.6 and 47 are all common.
Figures use the 2026/27 rates and rules described above, are rounded to the nearest pound, and were last checked against GOV.UK on 25 September 2026.
Assumptions and limitations
- Full-time hours default to 37.5 and full-time days to five. Change them to match your employer, because a 35-hour or 40-hour full-time week changes the answer.
- Tax and National Insurance use the 2026/27 rates and thresholds with a standard tax code and no other income. A second job, benefits in kind or a K code will change the deductions.
- Pension contributions are treated as deducted before tax (net pay arrangement), which is how most workplace schemes work. Relief-at-source schemes give the same result for basic-rate taxpayers.
- Term-time pay is scaled by the paid weeks you enter; employers calculate this in slightly different ways, so treat the result as a close estimate rather than a contractual figure.
- Holiday entitlement is pro-rated on the working week and floored at the statutory 5.6 weeks. Bank holidays are treated as part of the full-time allowance you enter.
- The calculator does not check the minimum wage. If your pro-rata hourly rate is below £12.71 (21 and over), use the minimum wage calculator.
Official sources
The figures used by this calculator come from the following official pages. Read how we check our figures.
- Part-time workers' rights — GOV.UK — Equal treatment and pro-rata pay and holiday
- Income Tax rates and Personal Allowances — GOV.UK
- National Insurance rates and categories — GOV.UK
- Repaying your student loan — GOV.UK — 2026/27 repayment thresholds
- Holiday entitlement — GOV.UK — 5.6 weeks pro-rated for part-timers
Further reading on IncomeFix
- Take-home pay calculator — The full breakdown for any salary
- Holiday entitlement calculator — Starters, leavers and irregular hours
- Benefits calculator — Part-time earnings often qualify for Universal Credit
- How to read your payslip
Related Tools
Frequently Asked Questions
What does pro rata mean in a job advert?
Pro rata means in proportion. A job advertised at £30,000 pro rata pays £30,000 to someone working full-time hours, and a proportionate share to anyone working fewer hours. Three days out of five earns 60% of the salary, so £18,000.
How do I calculate a pro-rata salary?
Divide your weekly hours by the full-time weekly hours, then multiply the full-time salary by that fraction. On a 37.5-hour full-time week, 22.5 hours is 22.5 ÷ 37.5 = 0.6, so a £35,000 salary becomes £21,000. Using days gives the same result: 3 ÷ 5 = 0.6.
Is a pro-rata salary taxed differently?
No. Tax and National Insurance are charged on what you actually earn in the year, using the same £12,570 Personal Allowance and bands as everyone else. Because the allowance is a bigger share of a smaller salary, part-time pay is taxed at a lower average rate: £21,000 loses about 11% to tax and NI, £35,000 loses about 18%.
What is the pro-rata salary for £30,000 at three days a week?
£18,000 a year (£30,000 × 3 ÷ 5). After income tax of £1,086 and National Insurance of £434.40 that is £16,479.60 a year, or about £1,373 a month, with no pension or student loan deductions.
How is holiday worked out on a pro-rata salary?
Holiday is pro-rated on your working week. The statutory minimum is 5.6 weeks, so three days a week gives 16.8 days and 22.5 hours a week gives 126 hours. If full-timers get more than 28 days, you get the same proportion of their allowance.
How does term-time only pay work?
Term-time contracts pay for the weeks you work plus pro-rata holiday, typically 44 to 47 paid weeks out of 52, and spread the total over 12 equal monthly payments. The calculator applies the hours fraction first and then the paid-weeks fraction, so a £28,000 FTE role at 30 hours for 44 weeks pays £18,953.85.
Do part-time workers have to get the same hourly rate as full-time staff?
Yes. Under the Part-time Workers (Prevention of Less Favourable Treatment) Regulations 2000, part-timers doing similar work must get the same hourly rate, the same overtime rate once they exceed full-time hours, and pro-rata access to holiday, sick pay, pensions and bonuses.