Pro-rata holiday calculator (UK)
Work out statutory holiday entitlement for part-timers and mid-year starters or leavers - based on the 5.6-week minimum or your own company allowance.
The person
Statutory minimum is 5.6 weeks (capped at 28 days). Pro-rata figures are rounded UP to the nearest half day - you may round up further, but never down below the statutory minimum. Bank holidays: whether they're inside or on top of the allowance depends on the contract wording.
Multiply the days worked per week by 5.6 to get the statutory annual entitlement (capped at 28 days), then multiply by the fraction of the leave year the person is employed. A 3-day-a-week worker gets 16.8 days a year; if they join halfway through the leave year, 8.4 - which most employers round up to 8.5.
How do you calculate pro-rata holiday for part-time staff?
The statutory formula is days per week × 5.6:
| Days per week | Calculation | Statutory minimum |
|---|---|---|
| 5 days | 5 × 5.6 | 28 days |
| 4 days | 4 × 5.6 | 22.4 days |
| 3 days | 3 × 5.6 | 16.8 days |
| 2 days | 2 × 5.6 | 11.2 days |
| 6 days | 6 × 5.6 = 33.6, capped | 28 days |
If your company gives more than the minimum (say 25 days plus bank holidays for full-timers, i.e. 33 for a 5-day week), scale the same way: a 3-day worker gets 33 × 3⁄5 = 19.8 days. Enter your full-time allowance in the calculator to use your own basis. See UK annual leave explained for how the 5.6 weeks works, and whether bank holidays count within it.
How does it work for a mid-year starter?
Multiply the annual figure by the months (or days) remaining in the leave year. Someone starting on 1 September with a January-to-December leave year works 4 of 12 months: 28 × 4⁄12 = 9.33, rounded up to 9.5 days. Rounding up to the nearest half day is standard practice; rounding down below the statutory figure isn't allowed (gov.uk).
What about leavers?
Same sum in reverse: entitlement accrued to the leaving date, minus holiday already taken. Anything accrued but untaken must be paid in the final pay; if they've taken more than accrued, you can only deduct it if the contract says so.
Do bank holidays change the maths?
Only via the contract wording. “28 days including bank holidays” and “20 days plus bank holidays” describe the same total for a Monday-to-Friday full-timer but behave very differently for part-timers - the classic problem is the part-timer who never works Mondays, where a “plus bank holidays” policy needs a pro-rata top-up to stay fair. Full detail in do bank holidays count towards annual leave?
Frequently asked questions
How do I calculate pro-rata holiday entitlement?
Multiply the days worked per week by 5.6 for the statutory annual minimum (capped at 28 days), then multiply by the fraction of the leave year the person is employed, rounding up to the nearest half day. A 3-day-a-week worker gets 16.8 days a year.
What is the pro-rata entitlement for a mid-year starter?
The annual entitlement multiplied by the months remaining in the leave year. Someone starting 1 September with a January leave year gets 4/12 of the annual figure - 28 x 4/12 = 9.33, normally rounded up to 9.5 days.
Can holiday entitlement be rounded down?
No - not below the statutory minimum. Employers may round up (to the nearest half or full day) but rounding down below the 5.6-week statutory figure is not permitted.
Do bank holidays count in the pro-rata calculation?
Bank holidays can count towards the 5.6-week minimum. Whether the allowance is expressed as including or plus bank holidays depends on the contract; part-timers who don't work Mondays usually need a pro-rata top-up under a plus-bank-holidays policy.
This calculator applies the statutory rules as published and shows its working, but it cannot know your contracts, your policies or anything unusual about the case. Treat the figure as a starting point, and take advice on anything contested or expensive.
Never do this sum again
CoDash works out every person's entitlement from their working pattern automatically - part-timers, mid-year starters, carry-over and half days included - and shows the whole team's leave on one calendar.