Irregular hours
Calculate holiday pay for irregular shift patterns
Work out your annual leave in days and hours — full-time, part-time, NHS, irregular hours and more.
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Almost every worker — not just employees on permanent contracts, but almost anyone classed as a "worker", including agency staff and people on casual or zero-hours arrangements — has a legal right to 5.6 weeks of paid annual leave each year. In Great Britain, for most workers, that figure is not one number in one place: it's two separate entitlements added together. Regulation 13 of the Working Time Regulations 1998 (WTR) gives 4 weeks. Regulation 13A, added for leave years starting on or after 1 April 2009, adds a further 1.6 weeks. Add them and you get 5.6 weeks — and it's reg 13A, not reg 13, that also caps the combined total at 28 days, since that's the regulation dealing with the combined entitlement.
Two groups get their leave under different rules. For leave years starting on or after 1 April 2024, regulations 13 and 13A no longer apply to irregular-hours and part-year workers: they build up leave as they work, under regulation 15B (see the irregular hours calculator). And the 1998 Regulations cover Great Britain only. Northern Ireland has its own Working Time Regulations (Northern Ireland) 2016, with the same figures: regulation 15 gives 4 weeks and regulation 16 adds 1.6 weeks, capped at 28 days.
"5.6 weeks" and "28 days" are the same thing only for a worker on a standard five-day week — for anyone else, the two figures diverge, which is exactly why so much of this page is about converting one into the other correctly.
Almost every question this site gets boils down to one of three variables. Once you know which one applies to you, you know which calculator to reach for.
A fixed salary makes a week's pay easy to state. Pay that varies — with overtime, commission, or hours worked — does not, and the law has to define a reference period to average it over. In England, Scotland and Wales, the reference period for holiday pay is 52 weeks, not the 12 weeks used for other purposes such as redundancy pay under the Employment Rights Act 1996. The 52-week rule has applied since 6 April 2020, via reg 16 of the WTR, which applies the Employment Rights Act's pay rules to holiday pay with that modification. In Northern Ireland it is still 12 weeks: reg 20 of the Working Time Regulations (Northern Ireland) 2016 uses the 12-week rules in the Employment Rights (Northern Ireland) Order 1996.
If your hours are fixed and predictable, the 5.6-week rule applies in the straightforward way this page works through below. If your paid hours vary week to week, or you only work part of the year with unpaid gaps in between, you're in a different statutory category — reforms that took effect from 1 January 2024 created specific rules for "irregular hours" and "part-year" workers, including a different, lawful way to pay rolled-up holiday pay that doesn't exist for anyone else.
The worked example below assumes a full leave year, worked in full. Join partway through a leave year, or leave before it ends, and you only accrue a proportion of the 5.6 weeks — and if your employment is ending, the outstanding balance has to be paid out under a specific statutory formula rather than simply carried forward.
Take the simplest possible case — a worker on a standard five-day week, employed for a full leave year, with no sickness, no mid-year changes, nothing unusual.
Start from the two regulations: 4 weeks (reg 13) + 1.6 weeks (reg 13A) = 5.6 weeks. For a worker whose normal working pattern is 5 days a week, a "week" of leave is worth 5 days of leave, so:
The same sum pro-rates cleanly for anyone working fewer days. A worker on 3 days a week gets:
If that 3-day worker's contract is stated in hours rather than days — say, 6-hour shifts, for 18 hours a week — the days figure converts to hours the same way, by multiplying by the length of a normal working day:
Every figure above is shown to the precision it's actually used at, so multiplying the numbers on the page reproduces the result exactly — there's no hidden rounding step between the days figure and the hours figure.
The calculation above only works cleanly because every variable in it is fixed and simple. Change any one of them and you need a different tool, not a variation on the same sum:
A handful of points trip up payroll teams and workers alike, usually because the intuitive assumption is wrong.
Calculate holiday pay for irregular shift patterns
Holiday calculations for rotating shift schedules
Calculate holiday pay owed on leaving employment
Holiday accrual during maternity or parental leave
Check for overlapping bank holidays in your leave
Calculate AfC annual leave for NHS Agenda for Change staff
Calculate 12.07% holiday pay for irregular hours and part-year workers
Work out entitlement when starting or leaving a job mid-year
Divide your contracted weekly hours by the number of days you work each week to get the length of your average day, then multiply by your entitlement in days. For example, 37.5 hrs ÷ 5 days = 7.5 hrs/day × 28 days = 210 hours. That is the same as 5.6 weeks of 37.5 hours.
It depends on your employer. Model A (top-up) adds bank holidays on top of your 28 days (e.g. 28 + 8 = 36 days). Model B (inclusive) means bank holidays come out of your 28 days, leaving you fewer days to book freely. Check your employment contract or see GOV.UK.
Pro-rata holiday is calculated using calendar days. Divide the number of days employed in the leave year by the total days in the leave year, then multiply by your full entitlement. Employers can never round the result down. Per ACAS guidance, rounding up to the nearest half day is mandatory during your first year of employment; after that it's optional, and some employers track the exact decimal figure instead.
Model A (top-up): bank holidays are given in addition to your annual leave. For example, 25 days leave + 8 bank holidays = 33 days total. Model B (inclusive): bank holidays count as part of your annual leave. For example, 25 days total of which 8 are bank holidays, leaving 17 days to book freely.
If a bank holiday falls on a day you do not normally work, there is no automatic right to a day in lieu. Your employer cannot require you to use that day as part of your holiday entitlement, but whether you get any alternative time off depends on your contract. Check your contract or ask HR to see whether bank holidays are included in your leave or given on top.
Part-time workers get the same statutory minimum as full-time workers, pro-rated to their hours. The legal minimum is 5.6 weeks' leave per year. If you work 3 days a week instead of 5, you receive 5.6 × 3 = 16.8 days. The 28-day cap only affects people working more than 5 days a week, so it never reduces a part-timer's figure. Bank holidays are not automatically pro-rated: an employer may include them in your allowance, give them on top, or count only those falling on your working days. Check your contract or ask HR.
Any statutory holiday you have accrued but not taken by the time your employment ends must be paid out in your final pay packet — this is called payment in lieu of accrued holiday. Your employer cannot simply withhold it. You get a week's pay for each week of leave you have not taken. If you get the same pay for your normal hours every week, that is your normal week's pay under your contract — not an average, so a recent pay rise counts in full. If your pay varies from week to week, it is your average over the last 52 weeks in which you were paid (or the complete weeks you have worked, if fewer than 52) in England, Scotland and Wales. In Northern Ireland the average is taken over 12 weeks. If you have taken more holiday than you have accrued, your employer may deduct the overage from your final pay if your contract allows it.
It depends why you didn't take it. Normally your statutory 5.6 weeks (28 days for a 5-day week) must be used in the leave year it's due, or it's lost. If your contract allows it, up to 1.6 weeks (8 days for a 5-day week) of that can carry over. If you work irregular hours or part of the year, your contract can let part of your leave carry over, and the law sets no number of weeks. If long-term sickness stopped you taking leave, you can carry over up to 4 weeks (all of it if you work irregular hours or part of the year), but it must be used within 18 months of the end of that leave year. If maternity or other statutory family leave stopped you taking leave, your employer must let it carry over automatically — this doesn't need their agreement. And if your employer didn't give you a reasonable chance to take your leave, encourage you to, or warn you it would be lost, you can also carry over up to 4 weeks (again, all of it if you work irregular hours or part of the year). In Northern Ireland there are no separate rules for irregular hours or part of the year: there, a contract can let up to 1.6 weeks carry over, and sickness or your employer's failure lets up to 4 weeks carry over, whatever your hours. Any contractual leave above the 28-day statutory minimum follows whatever your contract says.
You continue to accrue statutory annual leave throughout your notice period, whether you are working it or on garden leave. Entitlement accrues daily based on your contracted hours. If you have unused leave when you leave, it must be paid out. If your employer wants you to use up leave during your notice period, the default rule is that they must tell you at least twice as many days in advance as the number of days they want you to take (e.g. at least 10 days' notice to take 5 days' leave). Your contract, or a workforce or collective agreement, can change this rule or remove it, so check it first.