Pro Rata Calculator
Use this UK pro rata calculator to estimate part-time annual, monthly and weekly gross pay from full-time hours or working days, plus statutory or company holiday entitlement. To calculate pro rata salary, divide your part-time hours by the full-time hours, then multiply by the full-time annual salary. For example £30,000 × 22.5 ÷ 37.5 = £18,000 pro rata. Estimates only — your contract is the final word.
This hub combines six related UK calculators: pro rata salary (by hours), pro rata pay (by days), pro rata monthly gross pay, part-time salary, full-time equivalent (FTE) salary and pro rata holiday entitlement using the UK statutory 5.6 weeks formula. Everything runs in your browser — there is no sign-up.
Use it for part-time, term-time, reduced-hours and flexible working patterns to estimate annual, monthly and weekly gross pay, holiday days or holiday hours per year.
Note: Figures are gross (before Income Tax, National Insurance and pension contributions). Your contract, payslip and employer policy are the final answer for pay and holiday entitlement.
More Income and work calculators · All calculators · All guides
What this calculator does
Estimates pro rata annual, monthly and weekly gross pay from full-time salary and part-time hours or days, the full-time equivalent (FTE) salary from a part-time figure, and statutory or company holiday entitlement for part-time workers under UK rules.
Who it is for
UK part-time and reduced-hours employees, people considering switching from full-time to part-time, term-time workers, returning parents, job applicants comparing FTE vs part-time pay, HR teams and small business owners working out pro rata offers.
How to use it
Pick a section: salary by hours, pay by days, holiday, part-time salary, FTE or monthly gross. Enter the full-time salary and your full-time and part-time hours or days. Results update instantly with annual, monthly and weekly figures, the percentage of full-time and the formula used. Reset and copy buttons are available on every calculator.
How the calculation works
Pro rata salary = full-time salary × part-time hours ÷ full-time hours. Pro rata pay by days = full-time salary × part-time days ÷ full-time days. Monthly gross = pro rata annual ÷ 12. Weekly gross = pro rata annual ÷ 52. Full-time equivalent = part-time salary × full-time hours ÷ part-time hours. UK statutory holiday days = working days per week × 5.6, capped at 28. Statutory holiday hours = weekly hours × 5.6. Company pro rata holiday = full-time holiday days × part-time days ÷ full-time days.
Worked example
£30,000 full-time salary, 37.5 full-time weekly hours, 22.5 part-time weekly hours. Pro rata annual = £30,000 × 22.5 ÷ 37.5 = £18,000. Monthly gross = £1,500. Weekly gross ≈ £346.15. Working percentage = 60.0%. Statutory holiday for a 3-day week = 3 × 5.6 = 16.8 days. FTE check: £18,000 × 37.5 ÷ 22.5 = £30,000.
Assumptions and limitations
- Figures are gross (no Income Tax, National Insurance, pension or salary sacrifice deductions)
- UK statutory holiday minimum: 5.6 weeks per leave year, capped at 28 days for days-based entitlement
- Assumes regular weekly hours — irregular-hours and part-year workers may need the 12.07% accrual method introduced in April 2024
- Bank holidays may or may not be included in the 5.6 weeks — depends entirely on your employment contract
- Monthly figure uses annual ÷ 12 (calendar months), weekly uses annual ÷ 52
- Hourly equivalent assumes the same weekly hours every working week of the year
- FTE assumes the part-time and full-time roles share the same weekly working pattern
- This is general guidance, not legal advice — check your contract, ACAS and HMRC for definitive treatment of any specific case
Frequently asked questions
What does pro rata mean?
Pro rata is Latin for 'in proportion'. In UK pay terms, it means the salary or benefit has been scaled to match the share of full-time hours or days you actually work.
How do I calculate pro rata salary?
Divide your part-time hours by the full-time hours, then multiply by the full-time annual salary. £30,000 × 22.5 ÷ 37.5 = £18,000.
How do I calculate pro rata monthly pay?
Work out the pro rata annual salary, then divide by 12. £18,000 ÷ 12 = £1,500 gross per month, before tax and National Insurance.
How do I calculate pro rata holiday entitlement?
Multiply your working days per week by 5.6 (the UK statutory minimum), capped at 28 days. For hours, multiply weekly hours by 5.6. For company schemes above the minimum, multiply the full-time allowance by your days and divide by full-time days.
Is pro rata salary before or after tax?
The figures are gross — before Income Tax, National Insurance and pension contributions.
Does pro rata include bank holidays?
It depends on your contract. The 5.6-week statutory minimum can include bank holidays; they are not automatically given on top.
What is a full-time equivalent (FTE) salary?
FTE is what your role would pay if you worked full-time hours. FTE salary = part-time salary × full-time hours ÷ part-time hours.
Can I use this calculator for part-time work?
Yes — every section is built around UK part-time, term-time and reduced-hours patterns.
Is this calculator for UK employees?
Yes. The wording, statutory holiday formula and pay-frequency assumptions follow UK employment norms across England, Scotland, Wales and Northern Ireland.
Why does my employer's figure differ from this calculator?
Employers may use a different full-time hours figure, average pay over irregular hours, apply contract-specific bank holiday rules or count term-time only. Your contract is the final word.
Related calculators
- Car Salary Sacrifice Calculator — Car salary sacrifice gives up salary in exchange for a company car. You save Income Tax and NI on the sacrifice but pay BIK on the company c
- Day Rate Calculator — Enter your annual salary, hourly rate, or target income to calculate your equivalent day rate — or convert a day rate back to an annual figu
- EV Salary Sacrifice Calculator — EV salary sacrifice is highly tax-efficient because the EV Benefit in Kind percentage is just 4% for 2026/27. Income Tax + NI savings on the
- Full-Time Equivalent Salary Calculator — Use this full-time equivalent salary calculator to scale a part-time salary up to its full-time equivalent (FTE). FTE = part-time salary × f
- Holiday Accrual Calculator — Enter your annual entitlement and leave year dates to see how many days you have accrued so far and how many remain.
- Holiday Entitlement Calculator — Full-time UK workers are entitled to at least 28 days (5.6 weeks) of paid holiday per year including bank holidays. Part-time and irregular
Related guides
- How to Calculate Your Freelance Day Rate — A practical guide to setting your day rate as a freelancer or contractor, including salary equivalence and market benchmarks.
- How Overtime Pay Works in the UK — Understand your overtime pay rights, how it is taxed, and how different multipliers affect your earnings.
- How Holiday Accrual Is Calculated in the UK — Learn how holiday builds up over a leave year and how to check how much you have accrued so far.
- Inside IR35 Explained: What UK Contractors Need to Know — A clear guide to working inside IR35, how it affects your take-home pay, and what it means for your contract.
- How Holiday Entitlement Works in the UK — A practical guide to understanding your statutory holiday entitlement as a UK worker, covering full-time, part-time, and irregular working patterns.
- Outside IR35 Explained for UK Contractors — What outside IR35 means, how it affects your take-home pay, and the key differences between inside and outside IR35.
Sources and references
GOV.UK: Holiday entitlement (calculation guidance) — 5.6 weeks statutory minimum, capped at 28 days for days-based entitlement. GOV.UK: Calculating holiday pay for workers without fixed hours or pay. ACAS: Holiday entitlement guidance for part-time and irregular-hours workers. HMRC: PAYE pay-period guidance (annual ÷ 12 for monthly gross, ÷ 52 for weekly). These are general references; this calculator is not legal or tax advice.
Last updated
Last reviewed: 2026-05-20.