KnowMyPay

Pro-rata salary calculator

A full-time salary scaled to the hours or days you actually work. This shows the pro-rata gross and what reaches your account after tax and National Insurance.

Updated for 2026/27 Checked against gov.uk · last reviewed 2026-09-06
Pro-rata salary (gross)
£21,000 / year
60.0% of a £35,000 full-time salary · take-home about £18,640 a year.
Monthly take-home
£1,553
Income tax
£1,686
National Insurance
£674
The full-time figure the job is advertised at.
Use the same unit in both boxes, days or hours.

Take-home uses 2026/27 rates, England, Wales and Northern Ireland, standard code, no pension or student loan.

Full-time against part-time

BasisGrossTake-home
Full-time equivalent£35,000£28,720
Your pro-rata (60.0%)£21,000£18,640

How pro-rata pay is worked out

Pro-rata pay is the full-time salary multiplied by the share of the week you work. Divide your hours or days by the full-time hours or days to get the fraction, then apply it to the salary. Three days against a five-day week is 0.6, so a £30,000 full-time role pays £18,000 pro-rata. Days and hours both work, as long as both figures use the same unit.

Tax follows the actual pay, not the advertised salary. Your personal allowance stays at £12,570 whatever your hours, so a smaller salary shelters a larger share under it. That is why the take-home percentage on a part-time wage is often higher than on the full-time figure, and why very low pro-rata pay can fall out of income tax altogether.

Worked example

Take a £35,000 full-time salary and 3 days against a 5-day week. That is 60.0% of full time, so the pro-rata gross is £21,000. After £1,686 income tax and £674 National Insurance, the take-home is about £18,640 a year, near £1,553 a month.

Common questions

What does pro-rata salary mean?

Pro-rata means in proportion. A job advertised at a full-time salary but worked part-time pays a share of that figure, based on how many hours or days you do against the full-time week. Three days against a five-day week is three-fifths of the full salary.

What is £35,000 pro-rata for 3 days a week?

Working 3 days against a 5-day week is 60.0% of full time. On a £35,000 full-time salary that is about £21,000 gross a year, with a take-home of roughly £18,640 after tax.

How do I pro-rata by hours instead of days?

Enter your part-time hours as the part figure and the full-time hours as the full figure, for example 22.5 against 37.5. The tool divides one by the other, so days or hours both work as long as you use the same unit for both boxes.

Is a pro-rata salary taxed less?

You pay tax on the actual pro-rata pay, not the full-time figure. Because the personal allowance is fixed, a lower salary keeps more of each pound. A part-time salary under £12,570 pays no income tax at all, so the effective deduction is smaller than on the full-time equivalent.

Does pro-rata affect my holiday too?

Usually yes. Holiday entitlement is normally pro-rated the same way as pay, so part-time staff get a proportional share of the full-time holiday allowance. This tool covers pay only, not leave.

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