If you’re moving to a three-day week, the first question is always the same: what will I actually earn? A 3 day week pro rata salary calculator gives you the answer in seconds, but it’s worth understanding the maths behind it so you can check any figure your employer gives you — and spot the common traps that catch people out.
The short version: a three-day week is usually 0.6 of a full-time equivalent (FTE), so your salary is 60% of the full-time rate. But as you’ll see below, “usually” does a lot of heavy lifting in that sentence. The length of your working days, how your employer defines full-time hours, and whether bank holidays fall on your working days all change the final number.
How a 3-Day Week Salary Is Calculated
Pro-rata pay simply means pay in proportion to hours worked. The formula is:
Your salary = Full-time salary × (Your weekly hours ÷ Full-time weekly hours)
For a three-day week, most employers define full-time as five days. So the fraction is 3 ÷ 5 = 0.6, or 60%.
Take a full-time salary of £32,000 a year. On a three-day week:
£32,000 × 0.6 = £19,200 a year
That works out at £1,600 a month before tax and National Insurance. Simple enough — but only if your three days are the same length as a full-timer’s days. If full-time staff work 7.5-hour days (37.5 hours a week) and you work three 8-hour days (24 hours), the correct fraction is 24 ÷ 37.5 = 0.64, not 0.6. That difference is worth £1,280 a year on a £32,000 salary — not something to wave away.
The golden rule: always work from hours, not days. Days are a convenient shorthand, but hours are what your pay is actually based on.
Worked Example: From £35,000 Full-Time to a 3-Day Week
Let’s walk through a complete example. Priya is offered a role advertised at £35,000 full-time (37.5 hours a week, five 7.5-hour days). She negotiates a three-day week, working the same 7.5-hour days as everyone else.
Step 1: Find the FTE fraction.
Her hours: 3 × 7.5 = 22.5 hours a week.
Full-time hours: 37.5.
Fraction: 22.5 ÷ 37.5 = 0.6.
Step 2: Apply it to the salary.
£35,000 × 0.6 = £21,000 a year.
Step 3: Convert to monthly and hourly.
Monthly: £21,000 ÷ 12 = £1,750.
Hourly: £21,000 ÷ (22.5 × 52) = £21,000 ÷ 1,170 = £17.95 an hour.
Notice the hourly rate is identical to the full-timer’s: £35,000 ÷ (37.5 × 52) = £17.95. That’s exactly how it should be — pro-rata pay keeps the hourly rate constant. If your three-day salary gives you a lower hourly rate than your full-time colleagues, something has gone wrong in the calculation, and it’s worth querying.
3-Day Week Salaries at a Glance
The table below shows what a three-day week (0.6 FTE, equal-length days) pays at common full-time salaries. Use it as a quick reference, or run your own figures through our free pro rata salary calculator for an exact answer.
| Full-time salary | 3-day week salary (0.6 FTE) | Monthly (before tax) |
|---|---|---|
| £24,000 | £14,400 | £1,200 |
| £26,000 | £15,600 | £1,300 |
| £28,000 | £16,800 | £1,400 |
| £30,000 | £18,000 | £1,500 |
| £32,000 | £19,200 | £1,600 |
| £35,000 | £21,000 | £1,750 |
| £38,000 | £22,800 | £1,900 |
| £40,000 | £24,000 | £2,000 |
| £45,000 | £27,000 | £2,250 |
| £50,000 | £30,000 | £2,500 |
Remember: these figures assume your working days are the same length as a full-timer’s. If they aren’t, adjust the fraction using your actual hours.
When Three Days Isn’t 0.6 FTE
Here are the situations where the simple 60% figure doesn’t apply:
Different day lengths. As shown above, three 8-hour days against a 37.5-hour full-time week gives 0.64 FTE, not 0.6. Always check.
A four-day full-time week. Some employers have moved to a four-day full-time week. If full-time is four days and you work three, your fraction is 3 ÷ 4 = 0.75. On a £32,000 salary that’s £24,000, not £19,200 — a £4,800 difference.
Six-day operations. In retail or hospitality, “full-time” might mean five days out of a six-day operation, or the full-time week might be defined differently. Always ask what the employer’s full-time hours are before accepting a pro-rata figure.
Term-time only. If your three days are term-time only (say, 39 weeks a year instead of 52), there’s a second pro-rata calculation on top: 39 ÷ 52 = 0.75. Combined with 0.6 FTE, your overall fraction is 0.6 × 0.75 = 0.45. On £32,000, that’s £14,400.
Holiday Entitlement on a 3-Day Week
Your holiday is pro-rated too. Full-time workers get a minimum of 5.6 weeks’ paid leave a year (28 days for a five-day worker, including bank holidays). On a three-day week:
5.6 weeks × 3 days = 16.8 days a year.
That 16.8 days includes bank holidays — but only the ones that fall on your working days. If you work Monday to Wednesday, you’ll get the bank holidays that land on those days (most of them, since UK bank holidays are usually Mondays), but you won’t get extra leave for bank holidays on Thursdays or Fridays. Your employer should calculate your entitlement to reflect this; if they simply give you 16.8 days and then deduct every bank holiday, you’re being short-changed.
The Bank Holiday Trap
This is the single most common complaint from three-day-week workers. Imagine you work Monday to Wednesday. In a typical year, seven of the eight UK bank holidays fall on a Monday. You get those days off automatically — but they come out of your 16.8-day entitlement, leaving you just 9.8 days of holiday you can actually choose.
A colleague working Wednesday to Friday gets far fewer bank holidays landing on their working days, so more of their 16.8 days are theirs to choose. Same contract, same pay, noticeably different holiday reality.
Some fair-minded employers give part-timers a pro-rated bank holiday allowance on top of their leave (for a three-day worker, that’s typically 8 × 0.6 = 4.8 days added to the pot, with bank holidays that fall on working days then deducted). If yours doesn’t, it’s worth raising — the law requires part-timers to be treated no less favourably than full-timers, and several employment tribunal cases have turned on exactly this point.
Tax and Take-Home on a 3-Day Salary
A three-day salary often sits below the higher-rate tax threshold, which softens the blow of the pay cut. On £21,000 a year (from our earlier example), you’d pay:
- Income tax: 20% on earnings above the £12,570 personal allowance = roughly £1,686 a year
- National Insurance: 8% on earnings above £12,570 = roughly £674 a year
- Take-home: approximately £18,640 a year, or £1,553 a month
(Tax thresholds change, so treat these as a guide for the current tax year and check the latest figures.)
One useful side effect: if your three-day salary drops you below £12,570, you pay no income tax at all — though you’ll still pay National Insurance above its threshold.
Negotiating a 3-Day Week: What to Ask For
If you’re negotiating down from full-time (rather than applying for an advertised part-time role), go in with a checklist:
- The exact FTE fraction — calculated from hours, agreed in writing.
- Which days — and whether you can change them later.
- Bank holiday treatment — pro-rated addition or standard deduction?
- Overtime rates — what happens when you work a fourth day?
- Review clause — can you return to full-time if circumstances change?
Get the answers in the contract or a written variation letter, not just in an email from your manager. Handshake deals on hours have a habit of evaporating when managers change.
Other working patterns: 20 hours a week · 24 hours a week · 30 hours a week · 37.5-hour week · 40-hour week · 2 days a week · 4 days a week · 37.5 vs 40 hours · part-time hours tables · pro rata hours · days vs hours · examples by days per week
FAQs
Is a 3-day week always 60% of full-time pay?
Only if your three working days are the same length as a full-timer’s days and full-time means five days. If any of those assumptions change — longer days, a four-day full-time week, term-time working — the fraction changes. Always calculate from actual hours.
Do I get paid for bank holidays on a 3-day week?
You get the bank holidays that fall on your normal working days. Whether your employer adds a pro-rated bank holiday allowance on top of your 16.8 days’ leave depends on their policy — but they must not treat you less favourably than full-time staff overall.
Can my employer refuse a 3-day week request?
They can refuse a flexible working request, but they must handle it reasonably and can only refuse for specific business reasons set out in law. Since April 2024, employees can make a flexible working request from day one of employment.
Will going to 3 days a week affect my pension?
Your pension contributions are usually a percentage of your salary, so they’ll fall in cash terms — but the percentage stays the same. Check whether your employer’s contribution is also percentage-based (it usually is) and consider whether to increase your own contribution rate to stay on track.
Check Your Figures
Before you sign a new contract or accept a change to your hours, run the numbers yourself. A free pro rata salary calculator will give you the exact figure for your hours in seconds — and if your employer’s number doesn’t match, you’ll know exactly which question to ask.