Pro-rata is Latin for in proportion. When a job is advertised at a full-time salary but the role is part-time, or you work reduced hours, you're paid a share of that salary in proportion to the hours you actually do. The advertised figure is the full-time equivalent, not what a part-timer takes home.
This trips up a lot of job hunters. A role listed at "£35,000 pro-rata, 3 days a week" doesn't pay £35,000. It pays three-fifths of it, about £21,000, because you're working three days out of a five-day full-time week.
The sum is simple: your hours divided by the full-time hours, times the full-time salary.
Pro-rata salary = full-time salary × (your hours ÷ full-time hours)
You can measure in hours or days, whichever is easier, as long as both numbers use the same unit. The calculator above lets you switch between them.
A role is advertised at £30,000 full-time for a 37.5-hour week. You'll work 22.5 hours. Your pro-rata salary is £30,000 x (22.5 / 37.5) = £18,000. After Income Tax and National Insurance for 2026/27, that's roughly £16,200 take-home, about £1,350 a month. Because £18,000 is well within the basic-rate band, the tax is straightforward.
Salary isn't the only thing that gets pro-rated. Part-time workers are legally entitled to the same treatment as full-timers, in proportion. Holiday is the clearest one: the statutory minimum is 5.6 weeks of your normal working pattern. On 3 days a week that's 5.6 x 3 = 16.8 paid days a year, against the 28 days a five-day full-timer gets. Pension contributions, bonuses and other benefits are usually pro-rated the same way.
Once you know your pro-rata salary, drop it into the salary calculator to factor in student loan and pension, or use the hourly wage calculator to check the equivalent hourly rate.
The questions people ask most about part-time and pro-rata pay.
In proportion. It's the share of a full-time salary you get for working fewer hours. £30,000 full-time for 37.5 hours, working 22.5 hours, is £30,000 x (22.5 / 37.5) = £18,000.
Your hours divided by full-time hours, times the full-time salary. £28,000 full-time on a 5-day week, working 3 days, is £28,000 x (3 / 5) = £16,800. Use days or hours, as long as both match.
Adverts usually quote the full-time equivalent and add "pro-rata". So a £35,000 pro-rata role for 3 days a week actually pays about £21,000 for those days.
You're taxed on your actual pro-rata salary, not the full-time figure. The allowance and bands are the same, so many part-timers pay little or no higher-rate tax.
Yes, in proportion. The statutory minimum is 5.6 weeks of your pattern, so 3 days a week gives 5.6 x 3 = 16.8 paid days a year.
Tax figures use confirmed 2026/27 HMRC rates. Part-time rights per gov.uk.
Estimates based on 2026/27 tax rates, tax code 1257L, England/Wales/NI, no student loan or pension. For general information, not financial advice.