Pro-rata leave for part-time staff, with worked examples
How to work out a fair leave allowance for part-time staff in days or hours, including mid-year starters and people who change their hours.
7 min readFor owners, managers and payroll
In short
- Pro-rata means the same number of weeks off for everyone, not the same number of days.
- Count in days when a person's working days are all the same length; count in hours when they are not.
- A request should only use leave for days the person would have worked.
- When hours change mid-year, work out each part of the year separately and add them up.
- Agree one rounding rule and use it for everybody.
On this page12 sections
Giving a part-time colleague the same number of leave days as a full-timer sounds generous and fair. It is neither: someone who works three days a week and gets 25 days off has more than eight weeks away, while their full-time colleague has five. Giving them 'a bit less' by guesswork is not fair either. Pro-rata is the simple sum that sorts this out.
The examples below use a full-time allowance of 25 days. That figure is only an example. Minimum leave and the way part-time leave must be worked out differ between countries, so check the rules that apply to you and swap in your own numbers.
The principle: same weeks, fewer days
A full-timer working 5 days a week with 25 days of leave gets 5 weeks off. A fair part-time allowance gives the part-timer 5 of their own weeks off as well. For someone who works 3 days a week, that is 15 days.
Method 1: count in days
Use days when the person works full days of about the same length.
- Full-time: 5 days a week, 25 days of leave a year.
- Ben Carter works 3 days a week.
- 25 × 3 ÷ 5 = 15 days a year.
- Check: 15 days ÷ 3 days a week = 5 weeks off, the same as a full-timer.
Method 2: count in hours
Use hours when working days are different lengths, for example two long days and a short one. Counting in days breaks down here, because a 'day' of leave is worth more on a long day than a short one.
- Full-time: 40 hours a week. 25 days × 8 hours = 200 hours of leave a year.
- Emma Wilson works 20 hours a week: 8 on Monday, 8 on Tuesday, 4 on Wednesday.
- 200 × 20 ÷ 40 = 100 hours a year.
- A Monday off uses 8 hours. A Wednesday off uses 4 hours.
- Check: 100 hours ÷ 20 hours a week = 5 weeks off.
If Emma's leave were counted in days, taking every Wednesday off would use a whole day of leave for half a day of absence. Hours remove that problem.
Days or hours?
| Situation | Count in | Why |
|---|---|---|
| Same length of day, fixed days each week | Days | Easy for everyone to follow |
| Days of different lengths | Hours | A short day off should cost less than a long one |
| Hours change from week to week | Hours | There is no fixed 'day' to count |
| Mixed team | Whichever you can apply to everyone | One method is easier to explain and check |
- Situation
- Same length of day, fixed days each week
- Count in
- Days
- Why
- Easy for everyone to follow
- Situation
- Days of different lengths
- Count in
- Hours
- Why
- A short day off should cost less than a long one
- Situation
- Hours change from week to week
- Count in
- Hours
- Why
- There is no fixed 'day' to count
- Situation
- Mixed team
- Count in
- Whichever you can apply to everyone
- Why
- One method is easier to explain and check
Which days does a request use?
Leave should only be taken from the balance for days the person would have worked. If Ben works Monday to Wednesday and books a full week away, that is 3 days of leave, not 5. This sounds obvious, but it is the most common error when balances are kept by hand: someone counts the calendar days between two dates and takes off too many.
The fix is to record each person's working pattern (which days of the week they work) and count requests against that pattern.
Starting part way through the year
- Ben's full-year allowance is 15 days. The leave year runs January to December.
- He starts on 1 July, with 6 months of the leave year left.
- 15 × 6 ÷ 12 = 7.5 days for his first year.
Changing hours part way through the year
When someone moves between full-time and part-time, do not recalculate the whole year at the new rate. Work out each part of the year at the pattern that applied, then add the parts.
- January to June at 5 days a week: 25 × 6 ÷ 12 = 12.5 days.
- July to December at 3 days a week: 15 × 6 ÷ 12 = 7.5 days.
- Total for the year: 20 days.
- Take off what was already used before the change to get the balance left.
Public holidays and part-time staff
Public holidays cause more part-time disputes than annual leave does. Many holidays fall on the same weekday every year, so someone who never works that day might miss out while a colleague who always works it benefits every time.
Businesses deal with this in different ways. Some give a paid day only when the holiday falls on a day the person works. Others add a pro-rata share of the year's public holidays to the part-timer's allowance, so everyone gets the same proportion. What is required or usual depends on where you are, so check the rules that apply to you and then use one approach for everyone.
Rounding
Pro-rata sums rarely give round numbers. Pick a rule and keep it: for example, round up to the nearest half day, or keep two decimal places and let people take leave in hours. Rounding up is the safer habit, because rounding down can leave someone with less than they are owed.
A five-step routine
- Write down the full-time allowance and the full-time week (days or hours).
- Record each part-timer's working pattern: which days, and how long if days differ.
- Multiply the full-time allowance by the person's week and divide by the full-time week.
- Adjust for a part year (starter, leaver or a change of hours) by working out each part separately.
- Round with your one rule, record the sum, and tell the person the result.
How ClockinBee handles part-time time off
In ClockinBee each person has their own working-day pattern, so a request only counts the days that person works. A Monday-to-Wednesday worker who asks for a full week sees 3 days in the request preview, along with the balance that would be left, before they send it. Each person also follows a public holiday calendar, and holidays on it are not counted as leave.
Allowances live in time off policies. A policy sets the allowance, how it builds up (monthly, yearly or each pay cycle), and its carry-over limit and expiry. Policies can be given to individual people, so a part-timer can have a policy with their own pro-rata figure, and someone who changes hours can be moved to a different policy from that date.
ClockinBee keeps the counting consistent. It does not know what the law requires where you employ people, so confirm your allowances first.
Questions people ask
Is it fair that part-timers get fewer days?
Yes, as long as they get the same number of weeks. Fifteen days for a three-day week and 25 days for a five-day week both come to five weeks away from work.
What about someone whose hours are different every week?
Count in hours. Some businesses base the allowance on hours actually worked over a period instead of a fixed contract. How this must be done varies a lot by country, so check the rules that apply to you.
A public holiday falls on a part-timer's day off. Do they get another day?
That depends on your policy and local rules. Decide whether you give holidays only when they fall on a working day or give a pro-rata share to everyone, and apply the same answer to all part-time staff.
Do we round 7.5 days up to 8?
You can, and many do. If you prefer to keep halves, let people book half days so the allowance can be used in full.
How to do this in ClockinBee
- Set up time off policiesAllowances, how time off builds up, part-time, carry-over, notice and blocked dates.
- Public holiday calendarsGive each location or person the right public holidays, and add your own days.
- Give people different rulesHow ClockinBee decides which overtime rule, time off policy and holiday calendar applies to each person.
- Request time offPick your dates, see how many days it uses and what you will have left, then send.
Try it with your own team
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This guide is general information, not legal, tax or payroll advice. Working time, pay and time off rules differ by country and contract, so check the rules that apply to you.