Pro-rata salary calculator

How it works

Job adverts for part-time roles often quote a full-time equivalent (FTE) salary with “pro rata” after it. That means you get paid the same rate, scaled to the hours or days you work. This calculator does the scaling for you and then shows what you’d actually take home.

The formula

Pro-rata salary = full-time salary × (your hours ÷ full-time hours). You can use days instead of hours: 3 days out of 5 is 60% of the full-time salary. The full-time hours matter: 37.5 hours is common, but some employers use 35, 36, 37 or 40, and the same advertised salary gives a different hourly rate depending on which they use.

Why your take-home isn’t simply 60%

Income tax and National Insurance don’t scale down. The tax-free Personal Allowance of £12,570 and the National Insurance threshold of £12,570 stay the same whatever you earn, so a bigger share of a smaller salary is tax-free. That’s why the calculator shows take-home pay for both the full-time and the part-time salary.

Things a pro-rata salary doesn’t show

• Holiday entitlement is usually pro rata too, including bank holidays in many contracts.
• Pension contributions are normally a percentage of what you actually earn.
• If your pro-rata pay falls below the auto-enrolment trigger, your employer doesn’t have to enrol you in a pension, but you can ask to join.
• Your hourly rate must still be at least the National Minimum Wage for your age.

Hourly rate and part-time pay

A pro-rata salary has the same hourly rate as the full-time salary. To find it, divide the full-time salary by the full-time hours a week and by 52. That figure is useful for checking a part-time offer against an hourly job or against the National Minimum Wage for your age. Our hourly pages show the take-home pay for common hourly rates at different weekly hours.

If your hours vary from week to week, use your average hours over a typical period. If you’re moving from full-time to part-time with the same employer, check how your pension, sick pay and any benefits change, and whether overtime is paid at your basic rate until you reach full-time hours.

Some employers advertise term-time-only roles with a pro-rata salary as well. Those are scaled by the weeks you work in a year as well as the hours, so ask how the figure was worked out before comparing it with a year-round job.

Figures are for the 2026/27 tax year, verified against HMRC on 5 October 2026.

Worked example

A job pays £30,000 full-time for 37.5 hours a week. You work 22.5 hours, which is 60% of full-time, so your pro-rata salary is £18,000.

Full-time take-home would be £2,093.30 a month. Your take-home is £1,373.30 a month: 65.6% of the full-time figure. By days: 3 days a week on a £40,000salary is £24,000, or £1,733.30 a month after tax.