The formula
A pro rata salary scales a full-time salary by the share of the full-time working week that you do. You need three numbers: the full-time salary, the full-time working week, and your own working week. This page works as a salary prorated calculator in the plainest sense — it takes the full-time figure and prorates it by your fraction.
If your contract is written in days rather than hours, swap the hours for days: your days per week divided by the full-time days per week. Both routes give the same answer when the days are equal in length. Once you have the annual figure, monthly pay is the annual figure divided by 12, weekly pay is divided by 52, and the hourly rate is the full-time salary divided by (full-time hours × 52). That hourly rate never changes, which is the point of pro rata.
The panel under your result shows your FTE — your share of a full-time role written as a decimal. 0.60 FTE is the same fact as “60% of full time”, and it is the figure HR departments and pension schemes use. The FTE calculator converts between hours and FTE in both directions.
Calculate pro rata salary in three steps
- Find the full-time figures. Take the full-time annual salary and the full-time week (hours or days) from the job advert or your contract. Full time is not the same everywhere — 40, 37.5 and 35 hours are all common.
- Work out your fraction. Divide your hours by the full-time hours. 24 ÷ 40 = 0.6. This fraction is used again for your holiday entitlement, so it is worth writing down.
- Multiply. Full-time salary × your fraction = your pro rata annual salary. Divide by 12 for monthly pay.
The full method, including how to check the hourly rate and what to do when your days are different lengths, is in our guide: how to work out pro rata salary. If you are starting from the pay you need rather than the hours you have, the reverse pro rata calculator works the sum backwards.
Worked examples
Example 1 — 24 hours a week on a £40,000 job
Full time is 40 hours. Your fraction is 24 ÷ 40 = 0.6. Your salary is £40,000 × 0.6 = £24,000 a year. That is £2,000 a month and £461.54 a week. The hourly rate is £40,000 ÷ (40 × 52) = £19.23, exactly the rate a full-time colleague receives.
Example 2 — 3 days a week on a £35,000 job
Full time is 5 days. Your fraction is 3 ÷ 5 = 0.6. Your salary is £35,000 × 0.6 = £21,000 a year, or £1,750 a month. The fraction matches Example 1, so the pattern of the pay is the same.
Example 3 — 30 hours a week where full time is 37.5 hours
The full-time salary is £52,000. Your fraction is 30 ÷ 37.5 = 0.8. Your salary is £52,000 × 0.8 = £41,600 a year, or £3,466.67 a month. The hourly rate stays at £52,000 ÷ (37.5 × 52) = £26.67 an hour.
If the job is term-time only rather than all year round, there is a further paid-weeks step — see the teacher pro rata calculator, which is set up for school contracts. For holiday rather than pay, use the pro rata holiday calculator.
Common pro rata salaries
The same calculation, pre-worked for the salaries and patterns people ask about most. Find the full-time salary in the left column and read across to your pattern. Every figure is gross pay per year, before tax — the take-home estimate in the calculator above applies the tax to any of them.
| Full-time salary | 0.4 FTE · 40% | 0.5 FTE · 50% | 0.6 FTE · 60% | 0.8 FTE · 80% | 0.9 FTE · 90% |
|---|---|---|---|---|---|
| £20,000.00 | £8,000.00 | £10,000.00 | £12,000.00 | £16,000.00 | £18,000.00 |
| £25,000.00 | £10,000.00 | £12,500.00 | £15,000.00 | £20,000.00 | £22,500.00 |
| £30,000.00 | £12,000.00 | £15,000.00 | £18,000.00 | £24,000.00 | £27,000.00 |
| £35,000.00 | £14,000.00 | £17,500.00 | £21,000.00 | £28,000.00 | £31,500.00 |
| £40,000.00 | £16,000.00 | £20,000.00 | £24,000.00 | £32,000.00 | £36,000.00 |
| £45,000.00 | £18,000.00 | £22,500.00 | £27,000.00 | £36,000.00 | £40,500.00 |
| £50,000.00 | £20,000.00 | £25,000.00 | £30,000.00 | £40,000.00 | £45,000.00 |
Common mistakes
Using 52 weeks when your contract counts differently. Most salaried pro rata maths divides by 52, but some employers use 52.14 weeks (the average length of a year) for daily and weekly rates. The annual figure is the same either way; weekly and daily figures move by a few pence. If your payslip differs from the calculator by pennies, this is usually why.
Forgetting that holiday is pro rata too. The fraction that cuts your salary also cuts your holiday entitlement — 28 days becomes 16.8 days at three days a week. Staff who remember the pay and forget the holiday end up surprised in both directions. The holiday calculator uses the same fraction.
Comparing gross offers instead of take-home pay. A part-time salary is taxed more lightly than the same money earned full time, because the £12,570 personal allowance is a bigger share of it. Two offers that look 20% apart in gross pay may be only 17–18% apart after tax. Use the take-home estimate above before deciding.
Rounding the hourly rate. Payroll systems sometimes round the hourly rate down to the nearest penny before multiplying back up, which shaves a small amount off the annual figure. Your rate should be the full-time rate — £19.23 an hour on a £40,000, 40-hour job — applied exactly, not a rounded-down version of it.
Rates and assumptions used — 2026/27
The take-home estimates on this page use the rates below. They are the standard rates for an employee paid a salary; your own tax code and circumstances may differ.
Income tax — England, Wales and Northern Ireland
| Band | Rate | Applies to |
|---|---|---|
| Personal allowance | 0% | The first £12,570 of income. The allowance falls by £1 for every £2 of income over £100,000, and reaches £0 at £125,140. |
| Basic rate | 20% | Taxable income up to £37,700 (income up to £50,270 with the full allowance). |
| Higher rate | 40% | Taxable income above £37,700, up to £125,140 of total income. |
| Additional rate | 45% | Total income over £125,140. |
Income tax — Scotland
Scottish taxpayers (your tax code starts with S) pay Scottish rates on employment income. The personal allowance and its taper are the same as the rest of the UK.
| Band | Rate | Income range |
|---|---|---|
| Starter rate | 19% | £12,571 – £16,537 |
| Basic rate | 20% | £16,538 – £29,526 |
| Intermediate rate | 21% | £29,527 – £43,662 |
| Higher rate | 42% | £43,663 – £75,000 |
| Advanced rate | 45% | £75,001 – £125,140 |
| Top rate | 48% | Over £125,140 |
National Insurance — employees (Class 1, UK-wide)
| Earnings | Rate |
|---|---|
| Up to £12,570 a year | 0% |
| £12,570 to £50,270 a year | 8% |
| Over £50,270 a year | 2% |
Assumptions
- Pension: any pension percentage you enter is treated as salary sacrifice — taken from your pay before tax and National Insurance are worked out. If your scheme works differently (for example, relief at source), your figures will differ slightly.
- Not included: student loan repayments, tax codes other than the standard personal allowance, Marriage Allowance, Blind Person's Allowance, benefits in kind, and any savings or dividend income. The estimate covers employment income only.
- Figures are annualised from the yearly thresholds, as most salary calculators present them; payroll works month by month, so a single payslip can differ by a few pence.
Last checked: October 2026. Sources: HMRC and GOV.UK for UK rates and National Insurance; Scottish bands from the Scottish Government Budget 2026-27 (Scottish income tax is set by the Scottish Parliament and administered with Revenue Scotland). This is general information, not financial advice.
Frequently asked questions
A pro rata salary is a full-time salary adjusted for part-time work. You receive the same hourly rate as a full-time colleague, multiplied by the hours you actually work. Work 60% of the full-time hours and you receive 60% of the full-time salary.
Divide your hours by the full-time hours, then multiply the full-time salary by that fraction. For example, £40,000 × (24 ÷ 40) = £24,000 a year, which is £2,000 a month and £461.54 a week.
Use days instead of hours: divide your days per week by the full-time days per week. Three days out of five on a £35,000 job gives £35,000 × (3 ÷ 5) = £21,000 a year.
No. Pro rata means in proportion: your hourly rate stays the same as the full-time rate for the job. On a £40,000 job at 40 hours a week the rate is £19.23 an hour, and it is still £19.23 an hour if you reduce to 24 hours a week.
Most salaried part-time jobs pay monthly: the pro rata annual salary divided by 12. The calculator shows monthly, weekly, daily and hourly figures so you can match whichever period your payslip uses.