Pro Rata Salary Calculator UK 2026/27

How pro rata pay is worked out

Pro rata means "in proportion". Take the full time salary, divide by the full time hours, and multiply by your hours. £35,000 divided by 37.5 x 22.5 = £21,000. Holiday entitlement is prorated the same way: 28 days for five days a week becomes 16.8 days for three.

Why part time pay is taxed less than you expect

The personal allowance of £12,570 and the National Insurance threshold are the same whether you work two days or five, so a part time salary has a bigger share of untaxed pay. On £21,000 you pay income tax on only £8,430 and National Insurance on the same amount. On the full £35,000 you pay on £22,430. The effective rate on £21,000 is far lower, which is why going part time cuts your take-home by less than it cuts your gross.

Term-time and compressed hours

Term-time-only contracts are usually paid pro rata on weeks (for example 39 of 52 weeks plus holiday) and spread over twelve equal payslips. Compressed hours (full time hours in four days) are full time pay. If you are not sure which applies, the number to check on your contract is "annual salary (pro rata)".

The words on this page, in plain English

Take-home pay: The money that reaches your bank account after tax, National Insurance and other deductions. Also called net pay.
Gross pay: Your pay before anything is taken off. The salary in a job advert is gross pay.
Personal allowance: The first £12,570 you earn each year is not taxed. Earn over £100,000 and this allowance shrinks.
Tax code: A short code on your payslip, such as 1257L, that tells your employer how much untaxed pay you get. The numbers times 10 is your allowance.
PAYE: "Pay As You Earn": your employer takes tax and National Insurance out of each payslip and sends it to HMRC for you.
National Insurance (NI): A second tax on earnings that pays for the State Pension and some benefits. Most employees pay 8% on earnings between £12,570 and £50,270, then 2%.
Student loan plan: Which repayment rules apply to your loan. It depends on when and where you studied. Plan 2 covers most English students who started after 2012. Plan 5 those who started after 2023.
Salary sacrifice: You give up part of your salary and your employer pays it into your pension instead. You pay less tax and less National Insurance on it.
Scottish rates: If you live in Scotland you pay income tax in six bands set by the Scottish Parliament instead of the three bands used in the rest of the UK.

Questions people ask

What does pro rata mean on a job advert?

The salary shown is the full time figure. You will be paid the share that matches your hours. £30,000 pro rata at 20 of 37.5 hours is £16,000.

How do I calculate pro rata holiday?

Full time holiday x your hours divided by full time hours. 28 days x 22.5 divided by 37.5 = 16.8 days.

Do part time workers pay less tax?

Yes, in proportion and more: the untaxed allowance and the NI threshold are the same for everyone, so a smaller salary has a larger untaxed share.

Sources

The calculator on this page reads its rates from the same file these links are listed in. If a rate changes, the source list changes with it.

GOV.UK: Rates and thresholds for employers 2026 to 2027 (checked 25 October 2026)
GOV.UK: Holiday entitlement (checked 25 October 2026)

Produced by Apex Solutions, the development team that builds and supports TakeHomeFacts. Figures are checked against official worked examples on every build (see the latest run). An independent payroll reviewer is being appointed.
Last reviewed 25 October 2026, rates checked against the official source on 25 October 2026.

These figures are estimates to help you plan. Your payslip is the final word: PAYE works month by month, so a single payslip can differ a little, but the yearly totals match. See how we calculate and the accuracy tests.

More UK calculators

Take-home pay, Hourly Wage Calculator, Bonus Tax Calculator, National Insurance Calculator, Student Loan Repayment Calculator, Pension Salary Sacrifice Calculator, Scottish Income Tax Calculator, VAT