Part-time employees are entitled to the same annual leave as full-time staff. Not less. The same, adjusted proportionally for the hours or days they work.
That principle is straightforward. The calculation is where employers tend to go wrong, particularly when part-time workers have irregular hours, work different days each week, or join mid-year.
This post walks through how to calculate annual leave for part-time workers correctly, with worked examples, and covers the most common mistakes small employers make.
The legal position
Part-time workers have the right not to be treated less favourably than comparable full-time workers under the Part-Time Workers (Prevention of Less Favourable Treatment) Regulations 2000. That includes annual leave entitlement.
The statutory minimum in the UK is 5.6 weeks of paid annual leave per year. For a full-time employee working five days a week, that works out to 28 days as the statutory floor. Many employers offer more than this as a contractual benefit, such as 30 or 33 days. Whatever the full-time entitlement is at your company, the principle for part-time workers is the same: they receive the equivalent entitlement in proportion to the days or hours they work. The 5.6 weeks formula covers the statutory minimum. If your full-time employees get more than 28 days, part-time employees should receive their pro-rata share of that enhanced entitlement too.
Calculating leave for employees who work regular days
The simplest case is a part-time employee who works the same days each week, all year round. The formula is:
5.6 weeks multiplied by the number of days worked per week
Some examples:
- Works 3 days a week: 5.6 x 3 = 16.8 days
- Works 4 days a week: 5.6 x 4 = 22.4 days
- Works 2 days a week: 5.6 x 2 = 11.2 days
Fractions of a day should be rounded up to the nearest half day. So 16.8 days becomes 17 days, and 11.2 days becomes 11.5 days.
It is worth noting that 28 days is a cap on the statutory minimum, not a floor. An employee working six days a week would get 5.6 x 6 = 33.6 days on this formula, but the statutory entitlement is capped at 28. Any additional entitlement beyond that is contractual, not statutory.
Calculating leave based on hours worked
If a part-time employee works variable hours, or if it is easier to track leave in hours rather than days, the same principle applies but calculated in hours.
5.6 weeks multiplied by the number of hours worked per week
So an employee working 20 hours a week is entitled to 5.6 x 20 = 112 hours of paid annual leave per year.
Tracking leave in hours can be more precise for employees who do not work standard full days, and it avoids the awkwardness of part-days when someone takes a morning or afternoon off.
What about employees who work different hours each day?
Some part-time employees work, say, three days a week but for different lengths of time on each day. Perhaps they work six hours on Monday, four on Wednesday, and three on Friday.
In this case, tracking leave in hours is the cleaner approach. Their weekly hours are 13, so their annual entitlement is 5.6 x 13 = 72.8 hours, rounded up to 73 hours.
When they take a day off, you deduct the hours they would have worked that day. A Monday off costs six hours from their balance. A Friday off costs three.
Mid-year starters
If a part-time employee starts part-way through the leave year, their entitlement is pro-rated to reflect the proportion of the year they will work.
The formula is:
(Days worked per week x 5.6) divided by 12, multiplied by the number of complete months remaining in the leave year
So a part-time employee working three days a week who joins on 1 October, with a leave year ending 31 December, has three months remaining. Their entitlement for the remainder of the year is:
(3 x 5.6) / 12 x 3 = 4.2 days, rounded up to 4.5 days.
The same pro-rata logic applies when an employee leaves part-way through the year. Any unused statutory leave should be paid out on termination, and any leave taken in excess of their accrued entitlement can be deducted from final pay if the contract allows for it.
Bank holidays and part-time workers
Bank holidays add a layer of complexity for part-time workers, and it is worth getting this right. We covered it in detail in the bank holidays and part-time workers post, but the short version is this.
If your contract gives employees a set number of days including bank holidays, part-time employees should receive a pro-rata entitlement that already includes the bank holiday element. They should not receive the full eight bank holidays on top of a pro-rated allowance, and they should not lose out because all the bank holidays fall on days they do not work.
The cleanest approach is to give each employee their full pro-rata entitlement as a single leave allowance and let them book days flexibly, rather than trying to designate specific bank holiday dates.
Common mistakes to avoid
Giving part-time employees a flat number of days without adjusting for their working pattern. This is the most common error. Whatever your full-time entitlement is, part-time employees should receive their pro-rata share of it based on the days or hours they work, not the same flat amount.
Tracking leave in days when hours would be more accurate. For employees who work different hours on different days, days-based tracking leads to inconsistencies. A day off on a long day costs more than a day off on a short day, and a simple days-based system does not capture that.
Forgetting to pro-rate for mid-year starters. A part-time employee who joins in October should not receive a full year's entitlement.
Mixing up bank holidays with the rest of the leave allowance. As discussed above, bank holidays need to be handled carefully for part-time workers, particularly those who do not work on the days bank holidays fall.
Not rounding up fractions. Statutory guidance is to round fractions of a day up, not down. Rounding down is shortchanging the employee.
A quick summary
Part-time employees are entitled to 5.6 weeks of paid annual leave, calculated in proportion to the days or hours they work. The formula is 5.6 multiplied by contracted days (or hours) per week. Fractions round up. Mid-year starters are pro-rated. Bank holidays need separate attention. And for employees with variable hours across the week, tracking leave in hours is more accurate than tracking it in days.
Getting the calculation right protects you legally and, just as importantly, means your part-time employees feel they are being treated fairly, which they are entitled to be.
For the broader picture on annual leave rules in the UK, the guide to UK leave types is a good starting point. And if you are finding that managing different entitlements for a mix of full-time and part-time employees is becoming hard to keep on top of, Absently keeps leave records clear and accurate for every member of your team. Thirty days free, no credit card required.