What does pro rata mean?

Pro rata means "in proportion". A part-time salary is the full-time salary scaled to the hours you actually work — so half the hours means half the salary.

How is pro rata salary calculated?

Divide your weekly hours by the full-time hours, then multiply by the full-time salary. £40,000 full time at 37.5 hours, worked at 22.5 hours, is £24,000.

Do part-time workers pay less tax?

You pay tax and National Insurance on what you earn, with the same Personal Allowance and thresholds. A lower salary often means a lower average rate, and earnings under £12,570 are tax-free.

Pro rata salary calculator 2026/27

Working part of a full-time week? See your pro rata salary and what it leaves you after tax and National Insurance.

Full-time salary

Full-time hours per week Your hours per week

England, Wales & NI, 2026/27.

Your pro rata salary

2026/27

£24,000 a year

Income Tax: −£191
National Insurance: −£76

Monthly take-home

£20,800 a year

£1,733

Figures are monthly unless stated; rounded to the nearest pound.

Verified · 2026/27
21 June 2026

Effective rate —

Marginal rate — on your next £1

What it's worth in real terms

Your salary has the spending power of — in 2025 money — the pound has lost — since then. A rise of — would just keep pace.

Inflation: ONS Consumer Prices Index, latest May 2026.

How this was calculated

For the 2026/27 tax year (England, Wales & Northern Ireland) we apply your tax-free Personal Allowance, the Income Tax bands, employee National Insurance, and any student-loan repayment — each traced to a dated gov.uk/HMRC source. A pension contribution comes off before Income Tax (and before National Insurance too, for salary sacrifice). Over £100,000 the Personal Allowance tapers away, which is why the marginal rate jumps to about 60%.

The full method and every source is on our methodology page.

Built & maintained by the Pay Packet team · methodology sourced from HMRC · last reviewed 21 June 2026. About our figures →

How pro rata pay works

A pro rata salary scales a full-time wage to the hours you work. Take your weekly hours, divide by the full-time week, and multiply by the full-time salary. Your holiday, pension and most benefits are usually scaled the same way.

Tax and National Insurance are then worked out on your actual (lower) salary, with the full £12,570 Personal Allowance — so part-time workers often keep a higher share of their pay. For pension and student loan too, use the main take-home calculator.

Pro rata questions

What does pro rata mean?: Pro rata means "in proportion". A part-time salary is the full-time salary scaled to the hours you actually work — so half the hours means half the salary.
How is pro rata salary calculated?: Divide your weekly hours by the full-time hours, then multiply by the full-time salary. £40,000 full time at 37.5 hours, worked at 22.5 hours, is £24,000.
Do part-time workers pay less tax?: You pay tax and National Insurance on what you earn, with the same Personal Allowance and thresholds. A lower salary often means a lower average rate, and earnings under £12,570 are tax-free.