UK Pro Rata Salary Calculator
Convert a full-time UK salary into pro-rata annual, monthly and weekly pay based on the hours or days you actually work, plus your implied hourly rate.
Annual full-time equivalent gross salary.
How it works
Pro-rata pay simply means in proportion to a full-time role. If a job advertises a £30,000 salary for 37.5 hours a week, and you'll be working 22.5 hours, you should expect 22.5 ÷ 37.5 = 60% of the full-time salary, or £18,000 a year.
The formula
The formula is straightforward: pro-rata salary = full-time salary × (your hours ÷ full-time hours). Days work exactly the same way — 3 days out of a 5-day week is 60% pay, provided the length of each day is comparable. If your days vary in length, hours give a more accurate figure, since a role advertised as "3 days" could mean anywhere from 15 to 24+ hours depending on shift length.
Working out your hourly rate
Once you know your pro-rata weekly pay, dividing it by the hours you actually work each week gives your effective hourly rate — useful for comparing offers that quote different combinations of salary and hours, or for checking your pay meets National Minimum Wage requirements once averaged across the hours worked.
What else scales with hours
Part-time working affects more than just pay. Statutory holiday entitlement is pro-rata (5.6 weeks of your working week, not the standard 28 days). Employer pension contributions are usually a percentage of your actual pay, so they scale down too. Some benefits (private medical, gym memberships) are provided in full regardless of hours worked — check your offer letter.
The figure this calculator returns is gross. Once you know your pro-rata salary, you can drop it into the take-home pay calculator to see the after-tax amount you'll actually receive each month, taking account of the personal allowance, National Insurance and any student loan.
Worked example
A role is advertised at £30,000 full-time equivalent for 37.5 hours a week. You'll be working 22.5 hours a week (three 7.5-hour days).
- Ratio: 22.5 ÷ 37.5 = 60%.
- Pro-rata annual salary: £30,000 × 60% = £18,000.
- Monthly gross: £18,000 ÷ 12 = £1,500.
- Weekly gross: £18,000 ÷ 52 ≈ £346.15.
- Implied hourly rate: £346.15 ÷ 22.5 hours ≈ £15.38/hour.
Limitations of this calculator
- Assumes a simple linear ratio of hours or days — does not model unequal daily lengths unless you provide actual weekly hours.
- Shows gross pay only; does not deduct income tax, National Insurance, pension or student loan repayments.
- Does not account for shift premiums, overtime or unsociable-hours enhancements.
- Assumes a standard 52-week year — term-time-only or part-year contracts should pro-rata over weeks actually worked instead.
Frequently asked questions
How is pro-rata pay worked out?
Multiply the full-time salary by the ratio of your part-time hours (or days) to full-time hours. Someone on £30,000 full-time at 37.5 hours who works 22.5 hours (60%) earns £18,000.
Should I use hours or days?
Either — as long as you compare like with like. If you work 3 days in a 5-day full-time role, your ratio is 3/5. Days work well when contracted hours vary day to day; hours are more precise if your daily length differs.
Is the pro-rata figure gross or net?
Gross. To see what actually lands in your account, drop the pro-rata figure into the take-home pay calculator.
What about part-year working?
Part-year contracts (like term-time only) usually pro-rata over the year based on the weeks actually worked, including any paid holiday entitlement — check your contract.
Does this affect my pension?
Most workplace pensions contribute a percentage of your actual (pro-rata) salary, so contributions scale with your hours.
How do I work out my effective hourly rate?
Divide your pro-rata weekly pay by the hours you actually work each week. This calculator shows that hourly figure automatically once you enter your weekly hours.
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Official sources
Figures on this page follow official UK government guidance. Rates last verified: 27 August 2026. See our data sources and calculation methodology.
Estimates for general guidance only — not personalised financial advice.