Pro-rata holiday allowance explained

Joined partway through the year? Then you are entitled to part of the year's holiday. Here is how that part is worked out.

What “pro rata” means

Pro rata is Latin for “in proportion”. An annual holiday allowance is for a whole year of work, so if you work only part of a year, you get the same proportion of the allowance. Work half the year, get half the holiday.

The basic calculation

Prorated allowance = annual allowance × (time worked in the year ÷ whole year).

The “time worked” part can be measured in months or in days. Counting whole months is the simplest, and is what many employers do: start on 1 July with a 25-day allowance and you work 6 of 12 months, so you get 25 × 6 ÷ 12 = 12.5 days.

Starting mid-month

Few people start on the first of a month. A fair way to handle it — and the one Clockflux uses — is to count the rest of the first month by days, then add the full months that follow.

Starting on 16 March with 25 days a year:

March has 31 days, and 16 of them (the 16th to the 31st) are yours: 16 ÷ 31 = 0.52 months.
April to December are 9 full months.
Total: 9.52 months out of 12.
25 × 9.52 ÷ 12 ≈ 19.8 days.

Check your own start date with the pro-rata holiday calculator.

Accrual: when you can use the days

Your allowance tells you how much holiday you get in a year. Accrual decides when you can use it. Employers generally do one of two things:

Gradual (monthly) accrual — you earn one twelfth of your allowance as each month is completed. With 25 days, that is 2.08 days a month, so by the end of June you have earned 12.5. You can’t take holiday you haven’t earned yet.
Immediate accrual — the whole year’s allowance is available from 1 January, or from your first day if you start mid-year.

By 31 December both reach the same total. The difference matters if you want a long holiday early in the year, or if you leave partway through it.

Leaving partway through the year

The same arithmetic works in reverse. If you leave on 30 September after a full year from January, you have worked 9 months and earned 25 × 9 ÷ 12 = 18.75 days. Took more than that? Some employers deduct the difference from your final pay. Took less? Unused days are often paid out. The rules are in your contract.

Rounding, part-time work and public holidays

Employers round prorated allowances differently — down to a tenth, to the nearest half day, or up to a whole day. Part-time workers usually get an allowance proportional to their hours as well as to their time in the year. And whether public holidays are part of the allowance or on top of it varies by country and contract. Minimum entitlements also vary: the European Union guarantees at least four weeks of paid annual leave, for example. When in doubt, your contract and local law have the final word.

Keeping track of it all year

Clockflux handles both accrual modes and prorates your first year from your start date. Mark your holiday in the calendar as you take it, and it keeps your earned, used and available days current — and warns you if you are on course to go over. See holiday allowance.