Pro Rata Salary Calculator

Three days a week on a £35,000 role

The most searched version of the question. A full-time post pays £35,000 and the offer on the table is three days a week, on the same duties and the same grade.

£35,000 FTE · 3 of 5 days · England, Wales & NI · aged 21 or over

Gross falls by 40%, from £35,000 to £21,000.00. Take-home falls by 35.1%, from £28,719.60 to £18,639.60 — a gap of £10,080.00 rather than the £14,000.00 the headline implies. Statutory holiday is 16.8 days, which is three days a week multiplied by 5.6.

Reading a "£25,000 pro rata" advert for a 22.5-hour post

The advert leads with a number that nobody in the role will be paid. The hours are buried further down: 22.5 a week against a 37.5-hour full-time week.

£25,000 FTE · 22.5 of 37.5 hours · England, Wales & NI

The salary on offer is £15,000.00, not £25,000 — £1,193.30 a month after Income Tax of £486.00 and National Insurance of £194.40. Reading "pro rata" as an approximate or negotiable figure is the single most expensive misreading on a job board: it is the reference salary for a full-time person, and it is fixed.

Teaching assistant, 39 weeks, term-time only

Two reductions stack here, which is what makes term-time pay so hard to check by hand: the hours are below full-time, and the timetabled year is shorter than the calendar year.

£24,000 FTE · 32.5 of 37.5 hours · 39 weeks worked + 5.6 paid holiday weeks · 52.14 divisor

The hours fraction is 86.7% and the weeks fraction 85.5%, giving £17,791.12 gross and £1,360.77 a month. On a flat 52 divisor the same contract pays £17,840.00, £48.88 more. The calculator also flags something the pay slip will not: a £24,000 full-time equivalent over 37.5 hours is £12.31 an hour, below the £12.71 National Living Wage — pro-rating a rate that is already unlawful spreads it rather than curing it.

The four-day week at 30 hours

A compressed or reduced week negotiated on a £30,000 role, taking hours from 37.5 to 30 and days from five to four. The question is what the fifth day is really worth.

£30,000 FTE · 30 of 37.5 hours · 4 days a week · England, Wales & NI

Giving up 20% of gross costs 17.2% of take-home — £4,320.00 a year, or £360.00 a month. That is the figure to weigh against a day of childcare or a fifth commute, and it is materially smaller than the 20% most people budget for. Holiday drops to 22.4 days, because leave follows the days pattern rather than the hours.

An advertised rate that cannot lawfully be paid

A full-time post advertised at £18,000 for a 37.5-hour week. The pro-rata arithmetic is sound and the offer still is not lawful, which is why this calculator runs a minimum wage check on every result.

£18,000 FTE · 37.5 hours a week · aged 21 or over · England, Wales & NI

The implied rate is £9.23 an hour against a £12.71 floor from 1 April 2026, leaving the post £6,784.50 a year short of the legal minimum of £24,784.50. Pro-rating does not rescue it either: every fraction of an unlawful full-time rate is an unlawful part-time rate. Divide any offer back out to an hourly figure before you judge it.

What does "£25,000 pro rata" actually mean on a job advert?

It means £25,000 is the full-time-equivalent salary — what the role pays somebody working the employer's full-time hours — and that you will receive a proportion of it matching the hours or days you actually work. It is a reference figure, never the amount that reaches your bank account. At 22.5 hours against a 37.5-hour full-time week the offer is £15,000.00, and after Income Tax and National Insurance the take-home is £14,319.60 a year, or £1,193.30 a month. Adverts are not required to state the actual salary, and many do not, so the useful question at application stage is simply "what are the contracted hours, and what does that make the annual salary?" The phrase carries no negotiating implication either: it describes an arithmetic relationship, not an approximate or flexible number.

How much is £35,000 pro rata for 3 days a week?

Three days out of five is 0.6 of a full-time contract, so the gross salary is £21,000.00. On 2026/27 rates for England, Wales and Northern Ireland that produces Income Tax of £1,686.00 and employee National Insurance of £674.40, leaving take-home pay of £18,639.60 a year — £1,553.30 a month or £358.45 a week. Statutory holiday is 16.8 days, being three days a week multiplied by the statutory 5.6 weeks. If you work in Scotland the gross is identical and only the Income Tax differs, because National Insurance and the Personal Allowance are reserved across the whole UK.

Is pro rata pay calculated on hours or on days?

Either, depending on what the contract says, and the two can genuinely disagree. Pay normally follows hours, while statutory holiday follows the days-per-week pattern. Someone working 37.5 hours compressed into four long days is full-time for pay — 1.0 FTE, no reduction at all — but accrues 22.4 days of leave rather than 28, because 4 × 5.6 is 22.4. That is not an error and it is not less favourable treatment: four longer days of leave cover the same amount of time off as five shorter ones. The mismatch only causes trouble when payroll and HR use different bases without saying so, which is why this calculator asks for both patterns and shows you which one is driving the salary.

Do part-time workers get less holiday than full-time workers?

Fewer days, but exactly the same 5.6 weeks. GOV.UK gives the worked example directly: "if they work 3 days a week, they must get at least 16.8 days' leave a year (3 × 5.6)". The entitlement is measured in weeks of your working pattern, so a week off costs you three days if you work three days a week and five if you work five. Regulation 5 of the Part-time Workers (Prevention of Less Favourable Treatment) Regulations 2000 backs this up: a part-time worker has the right not to be treated less favourably than a comparable full-timer, and reg 5(3) requires the pro rata principle to be applied unless it is inappropriate. If your employer offers more than the statutory minimum, that contractual excess is normally pro-rated the same way.

How is term-time-only pay worked out?

There is no statutory formula — term-time pay is contractual, most often on National Joint Council terms in schools and local government. The usual approach multiplies the full-time-equivalent salary by the hours fraction, then by (weeks worked + paid holiday weeks) ÷ weeks in the year. For a £24,000 full-time equivalent at 32.5 of 37.5 hours over 39 weeks with 5.6 paid holiday weeks, that is £17,791.12 using the 52.14 calendar-week divisor. The salary is then normally paid in twelve equal instalments so that money still arrives during the school holidays. Because none of this is set by statute, the only reliable source is your own contract or your employer's pay policy — ask which divisor and which holiday-week figure they use, and check the result against the calculator above.

Do term-time-only staff still get 5.6 weeks of holiday?

Usually yes, and the test is whether you are paid during the gaps. In Harpur Trust v Brazel [2022] UKSC 21 the Supreme Court dismissed the employer's appeal on 20 July 2022 and held that a term-time music teacher's leave could not be scaled down for the weeks she did not work; the disputed Easter payment was £687.26 under the calendar-week method against £452.20 under the 12.07% method. Since then, for leave years beginning on or after 1 April 2024, "part-year workers" accrue leave at 12.07% of hours worked instead. GOV.UK defines a part-year worker as someone with periods of at least a week in the leave year that they are not required to work and for which they are not paid. A member of school support staff on an annualised salary is paid every month of the year, including the holidays, so that definition does not catch them and the full 5.6 weeks still applies.

Why is my take-home more than half a full-timer’s when I work half the hours?

Because the reliefs are fixed cash amounts rather than percentages. The £12,570 Personal Allowance and the £12,570 National Insurance primary threshold do not shrink when your hours do, so they shelter a much larger share of a smaller salary. On a £35,000 role at 0.6, gross drops by 40% but take-home drops by only 35.1% — from £28,719.60 to £18,639.60. Put the other way round, you keep 64.9% of a full-timer's net pay for 60% of the hours. The effect is strongest just above the Personal Allowance and fades away entirely once both salaries sit in the higher-rate band, where every extra pound is taxed at the same rate.

Can a pro rata salary be below the minimum wage?

Yes, which is why this page runs the check on every result. Divide the pro-rata salary by the hours you are actually paid for and compare it against the floor for your age: from 1 April 2026 that is £12.71 at 21 and over, £10.85 at 18 to 20, and £8.00 for under-18s and first-year apprentices. A £18,000 salary for a 37.5-hour week works out at £9.23 an hour, which is £6,784.50 a year below the £24,784.50 minimum and unlawful for anyone aged 21 or over. Pro-rating never fixes this, because a fraction of an unlawful hourly rate is still unlawful. GOV.UK is blunt about the consequences: underpaying the minimum wage is a criminal offence, HMRC can inspect an employer at any time, and an employer found to have underpaid must repay the arrears immediately and can be fined and publicly named.

How does dropping my hours affect my workplace pension?

Auto-enrolment runs on absolute thresholds that do not pro-rate, so reduced hours can change your pension far more than they change your pay. You must earn at least £10,000 a year to be automatically enrolled, and both your contribution and your employer's are calculated on qualifying earnings — the slice between £6,240 and £50,270 — rather than on your whole salary. Cutting a £20,000 salary in half takes you under the trigger, so your employer no longer has to enrol you, though you keep the right to ask to join and to receive contributions if you earn above the lower qualifying limit. If you are anywhere near £10,000, ask what happens to the employer contribution before you agree the new hours.

What is the difference between "pro rata" and "part-time"?

Part-time describes a working pattern; pro rata describes a method of calculation. They overlap constantly but are not the same thing. A term-time worker can be full-time for every week they are timetabled and still be paid pro rata, because the reduction comes from the weeks rather than the hours. Someone on a 37.5-hour compressed four-day week is not part-time at all and receives the full salary, with no pro-rating of pay. And pro rata does not apply only to salary: reg 5(3) of the Part-time Workers Regulations 2000 requires the pro rata principle to be applied to contractual benefits unless it is inappropriate, so holiday, sick pay above the statutory minimum, and normally bonuses are scaled the same way. That scaling is the equal treatment the regulations require, not a penalty for working fewer hours.