What pro rata is
Pro rata means that pay and holiday are shared out in proportion to the hours worked. A part-time employee receives the same hourly rate as a full-time colleague doing the same job, multiplied by fewer hours. Nothing about the rate changes — only the number of hours it is applied to. The tool at the top of this page is a pro rata pay calculator: feed it any full-time salary and any working pattern and it returns your share. The same proportion is used for holiday entitlement, and usually for pension contributions and bonuses as well.
People search for this calculation under several names. Some type “pro rata calc”, others “prorata calculator” as one word, and many add the country — “pro rata calculator uk” — because holiday rules differ between countries. They all describe the tool above.
If your contract is written in days rather than hours, use days in the same formula. Both routes agree when every working day is the same length. Where days differ in length — a long Monday and a short Friday — hours are the fairer measure, and payroll departments normally use hours.
Who uses a pro rata calculation
The calculation comes up whenever a job is not worked full time, all year round: staff reducing their hours after parental leave or before retirement, job shares, school staff on term-time only contracts, and NHS, council and university posts advertised as a fraction of a full-time role. It also matters when you start or leave a job part-way through a month or year, when pay is scaled to the days you were employed.
A post advertised at “£32,000 pro rata, 0.6 FTE” states the full-time salary and the fraction in one line. Converting it into real money — £19,200 a year — is a pro rata calculation, worth doing before you compare the post with any other job.
Popular patterns on a £35,000 salary
These are the working patterns people ask about most, all worked out on the same £35,000 full-time salary with a 40-hour full-time week:
| Working pattern | Share of full time | Pro rata salary |
|---|---|---|
| 4 days a week (32 of 40 hours) | 80% | £28,000.00 a year |
| 3 days a week (24 of 40 hours) | 60% | £21,000.00 a year |
| 2.5 days a week (20 of 40 hours) | 50% | £17,500.00 a year |
| School hours, 9am–3pm (27.5 of 40 hours) | 68.75% | £24,062.50 a year |
School-hours staff who also work term time only get one further step: the paid-weeks factor, which the teacher and term-time calculator applies. The pattern buttons inside the calculator load any of these examples for you to adjust.
Worked examples
| Situation | Working | Result |
|---|---|---|
| Part-time salary: £40,000 full time, 24 of 40 hours | £40,000 × (24 ÷ 40) | £24,000 a year (£2,000 a month, £19.23 an hour) |
| 3 days a week: £35,000 full time, 5-day week | £35,000 × (3 ÷ 5) | £21,000 a year |
| Holiday: 28 days full time, working 3 of 5 days | 28 × (3 ÷ 5) | 16.8 days a year |
| Irregular hours: 500 hours worked | 500 × 12.07% | 60.35 hours of holiday built up |
| Term-time only: £30,000 full time, 39 term weeks | £30,000 × (44.6 ÷ 52) | £25,730.77 a year (£2,144.23 a month) |
Every calculator on this site shows this working automatically, with your own numbers in place of the examples, directly under the result.
All calculators and guides
Pro Rata Salary Calculator
Salary only, with the full formula, further examples and salary questions answered.
Pro Rata Holiday Calculator
Holiday entitlement in days and hours, including the 12.07% method for irregular hours.
Teacher Pro Rata Calculator
Part-time and term-time only pay for teachers and school staff, with a worked example.
Part Time Salary Calculator
Part-time pay worked out from the full-time salary, plus your rights as a part-time worker.
FTE Calculator
Turn your hours into an FTE figure, and turn an FTE from a job advert back into hours.
Reverse Pro Rata Calculator
Start from the pay you need and work out how many hours a week it takes to earn it.
What Does Pro Rata Mean?
The plain-English definition, what “per annum pro rata” means in a job advert, and a glossary.
How to Work Out Pro Rata Salary
The step-by-step method, three worked examples, and the mistakes that make figures come out wrong.
Part-Time Holiday Entitlement
Your holiday rights as a part-time worker, bank holidays and term-time arrangements explained.
Pro Rata Rent Calculator
Part-month rent for moving in or out mid-month, both calculation methods shown side by side.
Pro Rata Hourly Rate Calculator
Convert an annual salary to an hourly rate and back, and check a pro rata offer is genuinely fair.
Pro Rata Date Calculator
Pro rata amounts worked out from dates: part-period salary, rent, subscriptions and premiums.
Frequently asked questions
Pro rata is Latin for “in proportion”. A pro rata salary is the full-time salary scaled down by the share of the full-time week you work. Work 24 hours where full time is 40, and you get 24 ÷ 40 = 60% of the full-time pay. Your hourly rate stays exactly the same. The longer explanation is on our page What does pro rata mean?
Divide your hours by the full-time hours to get your fraction, then multiply the full-time salary by that fraction. Example: £40,000 × (24 ÷ 40) = £24,000 a year, which is £2,000 a month. If your contract counts days instead of hours, divide your days by the full-time days — the method is identical.
It is the pay for a part-time version of a job, stated as an annual figure. Adverts often quote the full-time salary followed by “pro rata”, which means you receive the share of it that matches your hours. A £30,000 job advertised as pro rata, worked at 3 days out of 5, pays £18,000 a year before tax.
Multiply the full-time entitlement by the same fraction you use for pay. If full time is 28 days and you work 3 days out of 5, you get 28 × (3 ÷ 5) = 16.8 days. The legal minimum is 5.6 weeks of holiday for every worker, worked out pro rata for part-time staff.
Usually, yes. Most employers include bank holidays inside the 28-day statutory entitlement, so part-time staff receive a pro rata share of them. If a bank holiday falls on a day you do not normally work, many employers credit the value back into your remaining allowance. Check your contract to see which approach yours uses.
Term-time staff work around 39 weeks a year but are paid for those weeks plus 5.6 weeks of holiday: 44.6 paid weeks out of 52, a factor of 0.8577, applied after any hours fraction. The annual figure is usually spread evenly over 12 months, so you are still paid during the school holidays.