Accrued Holiday Calculator UK: How to Work Out Your Leave as You Earn It
Holiday doesn't arrive in one lump sum at the start of the year — it builds up, or accrues, throughout the year as you work. Understanding how much you've accrued at any given point matters when you start a new job mid-year, when you leave an employer, or when you're calculating outstanding leave. This guide explains the UK accrual rules, the formula behind them, and how to work out your figure quickly.
What does “accrued holiday” mean?
Accrued holiday is the proportion of your annual statutory leave entitlement that you have “earned” so far in your current holiday year. The UK statutory minimum is 5.6 weeks (28 days for a five-day-a-week worker), and this accrues evenly across the year rather than vesting all at once on 1 January or your contract anniversary.
For practical purposes, most employers use a simple monthly accrual method: you earn one-twelfth of your annual entitlement at the start of each month you work.
The UK holiday accrual formula
The core formula is:
Accrued days = (months worked in holiday year ÷ 12) × annual entitlement in days
For a standard full-time worker on the 28-day statutory minimum:
- After 1 month: 28 ÷ 12 = 2.33 days
- After 3 months: (3 ÷ 12) × 28 = 7 days
- After 6 months: (6 ÷ 12) × 28 = 14 days
- After 9 months: (9 ÷ 12) × 28 = 21 days
If your employer gives you more than the statutory 28 days, just substitute your actual contractual entitlement into the formula.
Worked example: full-time employee in a January holiday year
Suppose your holiday year runs January to December and your entitlement is 28 days. You want to know how much leave you've accrued by 1 April (three months in).
Accrued = (3 ÷ 12) × 28 = 7 days
If you've already taken 5 days, you have 2 days remaining of your accrued entitlement, though you're also likely to accrue more before the year ends.
Worked example: mid-year starter
You join on 1 August in a January–December holiday year. There are 5 months left (August through December), so:
Accrued by year end = (5 ÷ 12) × 28 = 11.67 days (round up to 12 in practice)
This is your full entitlement for the rest of that holiday year. In the following year you will accrue the full 28 days.
Worked example: part-time worker
A part-time employee working 3 days a week has an annual entitlement of 3/5 × 28 = 16.8 days. After 4 months:
Accrued = (4 ÷ 12) × 16.8 = 5.6 days
Most employers round to the nearest half-day, giving 5.5 days.
Does holiday accrue during sick leave?
Yes. Workers on sick leave continue to accrue statutory annual leave in full. If you are off sick for an extended period and your holiday year ends before you can take the leave, you are entitled to carry it over — up to 4 weeks (20 days for a full-time worker) — into the next holiday year. Some employers allow you to carry over the full 5.6 weeks; check your contract.
Does holiday accrue during maternity, paternity, or adoption leave?
Yes. Statutory and contractual holiday continues to accrue during all forms of family leave. Because it is often impractical to take leave during maternity leave, employers should allow the full accrued entitlement to be taken before or after the leave period, or carried over if necessary.
Holiday accrual on zero-hours and variable-hours contracts
Workers on zero-hours or casual contracts accrue holiday based on hours actually worked. The standard calculation is 12.07% of hours worked, which is the percentage equivalent of 5.6 weeks out of the 46.4 working weeks in a year.
Example: you work 20 hours this week. Accrued holiday = 20 × 12.07% = 2.41 hours.
Note that so-called “rolled-up holiday pay” — adding a 12.07% premium to each pay packet — was ruled unlawful by the Supreme Court in 2006 but was re-legalised for irregular-hours and part-year workers under the 2023 reforms to the Working Time Regulations. If your employer uses rolled-up pay, you cannot also take the equivalent paid leave separately; the two cannot be doubled up.
Accrued holiday pay when you leave a job
When you leave an employer, any accrued but untaken holiday must be paid out in your final pay packet — this is known as holiday pay in lieu. The calculation is:
Pay owed = (accrued days − days taken) × daily rate of pay
Daily rate is normally your weekly pay divided by the number of days you work per week. For workers with variable pay, the daily rate is averaged over the 52 weeks prior to leaving (the “52-week reference period” introduced by the Employment Rights Act 2023).
If you have taken more holiday than you have accrued when you leave, your employer may — if your contract permits it — deduct the overpayment from your final salary.
How to calculate your accrued holiday quickly
You can use the formula above manually, or let LeaveCalc's holiday entitlement calculator do the arithmetic for you. Enter your start date, your annual entitlement, and your holiday year dates, and it will show you exactly how many days you have accrued, how many you have taken, and how many remain — including a pro-rata figure if you started mid-year.
For part-time and shift workers, the pro-rata calculator handles the proportional entitlement automatically.
Common questions
Can my employer refuse to let me take accrued holiday?
Your employer can require you to take leave at certain times (such as during a Christmas shutdown) or refuse a specific request, but they cannot prevent you from taking your statutory entitlement altogether within the holiday year. If unused leave cannot be taken because the employer denied reasonable requests, the worker may be entitled to carry it over.
Does holiday accrue during the notice period?
Yes, holiday continues to accrue during garden leave and working notice periods. If your notice period runs to the end of the month, the leave accrued in that final month must still be factored into your final settlement.
What if my employer uses a different accrual method?
Some employers use a weekly accrual rate (1/52.18 of annual entitlement per week worked) rather than monthly. The end result is very similar; the monthly method is simply easier to administer for payroll purposes. Either is lawful provided it delivers at least the statutory minimum.
Use our free holiday entitlement calculator to work out your accrued leave in seconds.