Use this pro rata salary calculator to find out what a full-time salary is worth for the hours you actually work. Enter the advertised full-time salary, the full-time hours and your own hours, and it shows your yearly, monthly and weekly pay, your hourly rate and your share of statutory paid holiday.
Your pro rata pay (before tax)
- Per year
- –
- Per month
- –
- Per week
- –
- Hourly rate
- –
- Full-time share
- –
To see what you keep after tax, use the monthly take-home pay calculator.
The example shows a £30,000 full-time job worked for 22.5 hours a week over three days. That is 60% of full time, so the pro rata salary is £18,000 a year, or £1,500 a month.
What does pro rata mean?
Pro rata is Latin for “in proportion”. When a job advert says “£30,000 pro rata”, the £30,000 is what a full-time worker would earn. If you work fewer hours, a pro rata salary calculator pays you the same share of that salary as the share of hours you work.
Your hourly rate stays the same as a full-time colleague’s. Only the number of hours, and so the total pay, changes. That is why a part-time salary calculator and a pro rata salary calculator give the same answer: both scale the full-time figure by your hours.
How to use the pro rata salary calculator
- Enter the full-time salary from the job advert or your contract.
- Enter the full-time hours for that role. This is often 37.5 or 40 hours a week; check the advert or ask HR.
- Enter your hours and days per week. The days are only used to work out your holiday in days.
- Set the weeks you will be employed this year. Keep 52 for a permanent job, or lower it if you start or leave part-way through.
The pro rata salary formula
You can check any result by hand with one simple sum:
Pro rata salary = full-time salary × (your hours ÷ full-time hours)
For a part-year job, multiply the answer by the number of weeks you work and divide by 52. For example, a £30,000 full-time job worked for 30 out of 37.5 hours is £30,000 × 0.8 = £24,000 a year. If you only work 26 weeks of the year, you earn £24,000 × 26 ÷ 52 = £12,000 in that year.
Pro rata salary calculator examples
This table shows what the pro rata calculator gives for different full-time salaries at common part-time hours, using a 37.5-hour full-time week:
| Full-time salary | 15 hours (2 days) | 22.5 hours (3 days) | 30 hours (4 days) |
|---|---|---|---|
| £24,000 | £9,600 | £14,400 | £19,200 |
| £28,000 | £11,200 | £16,800 | £22,400 |
| £32,000 | £12,800 | £19,200 | £25,600 |
| £36,000 | £14,400 | £21,600 | £28,800 |
| £40,000 | £16,000 | £24,000 | £32,000 |
| £50,000 | £20,000 | £30,000 | £40,000 |
If the full-time week for your job is 40 hours, the same hours give a slightly smaller share. For example, 30 hours is 80% of 37.5 hours but 75% of 40 hours.
Pro rata salary calculator UK: starting or leaving mid-year
Pro rata also applies to time. If you join a company in October, you will only earn part of your annual salary in that tax year. Set the weeks in the calculator to the number you will actually work.
The monthly figure in the pro rata salary calculator always shows what you earn in a full month while you are employed. The yearly figure is the total you will earn in the weeks you entered.
Pro rata holiday entitlement
Almost every worker is entitled to 5.6 weeks of paid holiday a year, according to GOV.UK holiday entitlement rules. For someone working five days a week, that is 28 days. Part-time workers get the same 5.6 weeks, worked out on the days or hours they actually work:
| Days worked a week | Statutory paid holiday |
|---|---|
| 5 days | 28 days |
| 4 days | 22.4 days |
| 3 days | 16.8 days |
| 2 days | 11.2 days |
| 1 day | 5.6 days |
Workers on six days a week still get a maximum of 28 days, because the legal minimum is capped. Many employers offer more, and part-timers should get their pro rata share of any extra holiday too.
Your rights as a part-time worker
By law, part-time workers must not be treated less favourably than comparable full-time colleagues, unless the employer can justify it. That covers pay rates, holiday, pensions, training and sick pay. You can read the rules on GOV.UK part-time worker rights.
Benefits that cannot be split, such as a company car or health insurance, do not always have to be pro rata. If you are unsure, ask your employer how each benefit is worked out for part-time staff.
Compressed hours, job shares and term-time work
- Compressed hours: working 37.5 hours over four longer days is still full time, so your salary does not change. Only reduced hours are pro rata.
- Job shares: two people split one full-time role. Each person’s salary is pro rata to their share of the hours.
- Term-time only: schools often pay a pro rata salary for the weeks worked plus paid holiday, spread over 12 months. Check how your employer works it out, because the rules vary.
Three worked examples
Example 1: four days a week
Sam is offered a £36,000 job with a 37.5-hour full-time week, and asks to work four days of 7.5 hours. That is 30 hours, or 80% of full time. The pro rata salary calculator gives £28,800 a year, £2,400 a month, and 22.4 days of statutory holiday.
Example 2: mornings only on a 40-hour contract
Priya works 20 hours a week in a role where full time is 40 hours and pays £27,000. Her share is 50%, so she earns £13,500 a year. Her hourly rate is £12.98, which is above the National Living Wage of £12.71.
Example 3: starting part-way through the year
Tom starts a £32,000 full-time job and will work 20 weeks before the end of the tax year. In that time he earns £32,000 × 20 ÷ 52 = £12,307.69. His monthly pay while employed is still £2,666.67.
Bonuses, overtime and pension on a pro rata salary
- Bonuses linked to salary are usually pro rata too. A 10% bonus on £18,000 is £1,800.
- Overtime: extra hours up to the full-time level are often paid at your normal rate, and only hours beyond full time at an overtime rate. Check your contract.
- Pension: your contribution is a percentage of your pro rata pay. If you earn under £10,000 a year with one employer you are not auto-enrolled, but you can ask to join. Compare options with the salary sacrifice calculator.
Asking to work fewer hours
Employees in Great Britain can make a flexible working request from their first day in a job. You can make up to two requests in any 12 months, and your employer must reply within two months and can only refuse for a set list of business reasons.
Before you ask, run the numbers through the pro rata salary calculator so you know exactly what a change of hours will mean for your pay and holiday.
After tax: what you take home
A part-time salary often falls into a lower tax band, so you keep a bigger share of each pound. On £18,000 a year, for example, only the part above £12,570 is taxed. Use our monthly take-home pay calculator to turn your pro rata salary into what you will actually be paid.
On the minimum wage? The minimum wage salary calculator shows your pay for any hours. If you are paid by the hour rather than a salary, the hourly wage calculator converts your rate into weekly, monthly and yearly pay instead.
Frequently asked questions
How do I calculate pro rata salary?
Divide your hours by the full-time hours, then multiply the full-time salary by that figure. 22.5 ÷ 37.5 = 0.6, so a £30,000 job pays £18,000 pro rata. The pro rata salary calculator above does this for you.
What does £25,000 pro rata mean?
It means a full-time worker earns £25,000. If you work half the full-time hours, you will earn £12,500 a year.
Is a part time salary calculator the same as pro rata?
Yes. Both start from the full-time salary and scale it to your hours, so they give the same result.
Do part-time workers get bank holidays?
There is no automatic right to bank holidays off. They can be counted as part of your 5.6 weeks of statutory holiday, worked out pro rata.
Is my hourly rate lower if I work part time?
No. A pro rata salary keeps the same hourly rate as a full-time colleague. The calculator shows that rate so you can check it.
About this calculator
This pro rata salary calculator uses the standard UK method: your share of the full-time hours, and the weeks you work out of 52. Holiday uses the statutory 5.6 weeks, capped at 28 days. The rules were checked against GOV.UK on 5 November 2026.
Results are before tax and are estimates. Your contract shows how your own employer works out pay and holiday.