How UK statutory holiday is worked out
This pro rata holiday calculator follows the method GOV.UK publishes for statutory annual leave. Almost all workers are entitled to 5.6 weeks of paid holiday a year. For someone who works five days a week that is 28 days. The same 5.6 weeks apply to part-time workers, but the days are their own days: three days a week is 3 times 5.6, which is 16.8 days, and four days a week is 22.4 days. The statutory entitlement is capped at 28 days. Someone who works six days a week does not receive 33.6 statutory days. The cap cuts that figure back to 28. Many contracts give more than the legal minimum, and bank holidays are often counted inside the 5.6 weeks rather than added on top. The calculator shows the statutory floor. If you type a full-time contractual allowance above 28 days, it also shows the part-time share of that higher number, which is the full-time allowance multiplied by days worked and divided by five.
A worker with a fixed number of hours but days of different lengths can be counted in hours. GOV.UK's worked example is a 30-hour week over four days. The day entitlement is still the lower of 28 and 5.6 times 4, which is 22.4 days. The average working day is 30 divided by 4, which is 7.5 hours. Hours of leave are 22.4 times 7.5, which is 168. The page does that multiplication only when you type a weekly hour figure. It does not invent an eight-hour day. Compressed hours and shifts of unequal length belong in this hours method. A regular shift pattern of equal shifts can be described as the average number of shifts per week, which is shifts in the pattern divided by days in the pattern, times seven, and then treated as days worked per week.
Someone who starts part-way through a leave year does not receive the full 5.6 weeks for that year. In the first twelve months, regulation 15A accrues leave in twelfths. GOV.UK's view, which the guidance says is not legally binding, is that the first month begins on the first day of the job and the next month begins one month later, not necessarily on the first of a calendar month. On the first day the worker receives one-twelfth. Each later month started adds another twelfth, up to the pro-rated total for the rest of the leave year. A fraction of a day is rounded up. Below half a day it rounds up to the next half day. Above half a day it rounds up to the next whole day. An exact half stays as a half. The published examples land on 16.5 days for a five-day week that has seven months left in the year, and on 21 days for a four-day week with eleven months left. Five months of a five-day week, converted at a seven-hour average day, is 84 hours.
When someone leaves, regulation 14 of the Working Time Regulations pro-rates the year's entitlement by calendar days in employment, not by days actually worked. The leave year is 365 days, or 366 if it contains 29 February, even if the worker has already left before that leap day. Divide the inclusive calendar days from the start of employment in that leave year, or from the leave-year start if they were already employed, by the length of the leave year, and multiply by the full-year entitlement. A six-day week is still capped at 28 before that multiplication. This page multiplies the exact day count. GOV.UK's prose sometimes rounds the percentage first, so a displayed 10.7 can sit a fraction above the exact product.
Irregular hours and part-year workers are treated differently for leave years beginning on or after 1 April 2024. They accrue leave at 12.07 percent of the hours they have worked in the pay period, instead of receiving a fixed pot of days at the start of the year. The 12.07 percent figure is the one GOV.UK states. It is 5.6 statutory weeks divided by the 46.4 weeks that remain after those weeks are set aside. Type the hours worked in the pay period and the page applies that rate. It does not also add a fixed 5.6 weeks on top. For leave years that began on or before 31 March 2024, the older approach of estimating from average days or hours in a week can still be used, and the full-year and leaver modes on this page are that approach. A zero-hours contract does not remove the right to 5.6 weeks. It changes how the weeks are counted.
Two limits are easy to miss. First, the calculator does not add bank holidays. If the contract says the 28 days include the bank holidays in England and Wales, those days come out of the total, they are not extra. Scotland and Northern Ireland have their own bank holiday lists, and a contract may name them. Payment in lieu of untaken leave when employment ends is a separate calculation that uses a week's pay. This page stops at the number of days or hours. It does not know the worker's pay, rolled-up holiday pay, or whether leave was already taken.