Pro Rata Salary Calculator United Kingdom

When a job is advertised at a full-time salary but you work part time, your pay is the pro-rata amount, a proportion based on your hours. This calculator turns a full-time salary into your annual, monthly and weekly pay, the hourly rate behind it and your pro-rata holiday, so you can check a part-time offer quickly.

How pro-rata pay is worked out

Pro rata means in proportion. Divide your weekly hours by the employer’s full-time hours to get your percentage of full time, and apply it to the advertised salary. If full time is 37.5 hours and you work 22.5, that is 60%, so a £40,000 full-time salary pays £24,000. The calculator shows the percentage so you can see how your hours translate into pay.

Full-time hours vary

There is no single UK definition of full time: 35, 37.5 and 40 hours a week are all common, so the same part-time hours can be a different percentage at different employers. Twenty-five hours is 71% of a 35-hour week but only 62.5% of a 40-hour week. That is why the calculator asks for the employer’s full-time hours, which matter when comparing two part-time offers.

The hourly rate behind a salary

An hourly rate helps when comparing salaried and hourly roles or valuing overtime. The full-time salary divided by the full-time hours over the year gives the hourly rate, which is the same whether you work full or part time; your pro-rata salary is that rate times your hours. It also makes it easy to check a part-time offer against the minimum wage.

Pro-rata holiday

Part-time workers are entitled to the same holiday as full-timers in proportion to the time they work. If a full-time role gives 28 days, someone on 60% of full-time hours gets about 16.8 days. Enter the full-time entitlement in the advanced option and the calculator pro-rates it. The statutory minimum is 5.6 weeks, 28 days for a five-day week, and employers can count bank holidays within it.

A worked example

A role advertised at £40,000 for a 37.5-hour week, done in 22.5 hours, is 60% of full time. Your pro-rata salary is £24,000, £2,000 a month, at an hourly rate of about £20.51, with 16.8 days of holiday from a 28-day full-time entitlement. If full time were 40 hours, the same 22.5 hours would be 56.25%, and the pay £22,500.

How to use the calculator

Enter the full-time salary, the employer’s full-time hours and the hours you work, and add the full-time holiday entitlement in the advanced option. The result shows your pro-rata annual, monthly and weekly salary, the hourly rate, your percentage of full time and your pro-rata holiday days.

Assumptions and limitations

This is a straight proportion of hours, before tax; use a take-home pay or Income Tax calculator for the after-tax figure. It assumes pay scales with hours, which is normal for salaried roles but may not hold with shift premiums, term-time-only contracts or compressed hours. Holiday is pro-rated on the hours ratio; some employers calculate part-time leave in hours, or by the number of days worked each week, which can give a slightly different figure.

About This Pro Rata Salary Calculator

Use this pro rata salary calculator to get an instant estimate based on the figures you enter. Adjust the inputs above to match your situation, or browse all our calculators to plan your next step.