In the UK, part-time workers get the same 5.6 weeks of paid holiday as full-timers, calculated pro-rata to the days or hours they work. The basic formula is days per week × 5.6 = annual leave days. Bank holidays should be pro-rated separately to avoid less favourable treatment for staff who don't work Mondays.
The calculator uses the rules set out below. Read on to understand the legal basis and edge cases.
The legal basis
Part-time holiday entitlement in the UK sits at the intersection of two pieces of legislation. The Working Time Regulations 1998 set the statutory floor of 5.6 weeks of paid annual leave for almost all workers - covered in detail in our guide to UK annual leave entitlement. The Part-time Workers (Prevention of Less Favourable Treatment) Regulations 2000 then require that part-time staff are not treated less favourably than a comparable full-time colleague.
In practice, this means part-time workers are entitled to exactly the same 5.6 weeks of leave as full-timers - but expressed in proportion to their working pattern. A four-day-a-week worker gets 5.6 weeks' worth of four-day weeks. A three-day-a-week worker gets 5.6 weeks' worth of three-day weeks. Nobody loses out.
Three categories of part-time worker
Before you reach for a calculator, you need to know which type of part-time worker you're dealing with. Since 1 April 2024, UK law treats them differently.
The big change in April 2024 was that irregular-hours and part-year workers now accrue holiday based on hours actually worked, rather than getting a fixed annual entitlement up front. We cover the detail of those rules further down. For everyone else - the typical part-timer with set days each week - the old rules still apply.
Fixed-pattern part-timers: the formula
If your part-time worker has a contract specifying the same number of days each week, the calculation is simple. ACAS sets it out plainly: multiply the days they work each week by 5.6.
One important point on the cap: the statutory entitlement maxes out at 28 days, even for someone working 6 or 7 days a week. So while a 5-day worker gets the full 28 (5 × 5.6), a 6-day worker also gets 28 - not 33.6.
Worked examples
The most common part-time patterns in the UK are 4, 3, 2.5, and 2 days per week. Here is what the formula produces for each:
The fractional days can be used flexibly - typically by agreement with the manager to take a half day off, or to start late or finish early on a specific date.
If you offer more than the statutory minimum
Many UK employers offer 25 days plus 8 bank holidays, or 30 days inclusive of bank holidays. Whatever your enhanced full-time figure is, part-timers must receive the same package on a pro-rata basis. Use the same multiplier approach: divide the full-time annual leave by 5 (assuming a 5-day full-time week), then multiply by the part-timer's days per week.
For example, if your full-timers get 33 days inclusive of bank holidays:
- 4-day-a-week worker: (33 ÷ 5) × 4 = 26.4 days
- 3-day-a-week worker: (33 ÷ 5) × 3 = 19.8 days
Calculating in hours instead
If shift lengths vary day to day, days don't really capture the picture. In that case, work in hours. The principle is identical - just substitute hours for days.
So a part-timer working a stable 20 hours a week is entitled to 20 × 5.6 = 112 hours of paid annual leave per year. When they take leave, you deduct the actual hours they would have worked that day from the balance.
Bank holidays for part-timers
Bank holidays are the single most common source of part-time holiday disputes. There is no automatic statutory right to paid time off on a bank holiday - whether they count depends on the contract. For the full list of dates per nation, see our UK bank holidays 2026 and 2027 guide. There are two common approaches:
| Approach | What the contract says | How it works for part-timers |
|---|---|---|
| Inclusive | "28 days including bank holidays" | Bank holidays are deducted from the 5.6-week pro-rata entitlement. |
| On top | "20 days plus bank holidays" | Part-timers must get a pro-rata share of the bank holiday days too. |
The "on top" approach is where it gets interesting. If your full-timers receive 8 bank holidays in addition to their core leave, you have to give part-timers a proportional number of bank holiday days as well - even if those bank holidays don't fall on their normal working days.
Worked example: pro-rating bank holidays
3 ÷ 5 = 0.6
8 × 0.6 = 4.8 days
12 + 4.8 = 16.8 days total
Irregular-hours and part-year workers
For leave years that started on or after 1 April 2024, irregular-hours workers and part-year workers accrue holiday differently. The rules were changed by amendments to the Working Time Regulations following the Supreme Court ruling in Harpur Trust v Brazel, and the official guidance is set out in the GOV.UK reforms document.
Definitions matter here. ACAS defines them as:
- Irregular-hours worker: someone whose paid hours each pay period are wholly or mostly variable under their contract. Typically zero-hours, casual, or bank staff.
- Part-year worker: someone required to work only part of the year, with periods of at least one week where they are not required to work and are not paid. Term-time-only school staff are the classic example.
So if a casual worker puts in 70 hours during a monthly pay period, they accrue 70 × 12.07% = 8.45 hours of paid leave for that month. ACAS rounds part-hours down if under 30 minutes, up if 30 minutes or more, so this would round to 8 hours.
When working hours change mid-year
If a worker switches from full-time to part-time hours (or vice versa) partway through the leave year, ACAS guidance is clear: their entitlement should be recalculated from the date the change takes effect. Holiday already accrued under the old pattern is not affected.
Worked example
28 days × (3 ÷ 12) = 7 days
16.8 days × (9 ÷ 12) = 12.6 days
7 + 12.6 = 19.6 days
Common mistakes to avoid
These are the recurring errors that surface in ACAS conciliation cases and employment tribunal claims:
| Mistake | The fix |
|---|---|
| Ignoring bank holidays for non-Monday workers | Pro-rate the bank holiday allowance separately and let staff use it flexibly. |
| Applying 12.07% to fixed-pattern part-timers | Use days/hours × 5.6 for fixed schedules. Reserve 12.07% for irregular-hours and part-year staff only. |
| Rounding part days down | Always round up. Mandatory in year one, best practice afterwards. |
| Not recalculating when hours change | Recalculate from the date of the change. Don't disturb leave already accrued. |
| Excluding part-timers from enhanced contractual benefits | If full-timers get more than 5.6 weeks, part-timers get the same uplift on a pro-rata basis. |
| Treating overtime hours as ordinary working hours | Part-timers only qualify for overtime rates once they pass the comparable full-time hours threshold. |
Sources
Every claim in this guide is drawn from official UK government and statutory sources. If you're handling a tricky case, go directly to these:
| Source | What it covers |
|---|---|
| GOV.UK - Holiday entitlement | The 5.6-week statutory minimum and how to calculate it. |
| GOV.UK - Holiday entitlement calculator | Official calculator for all working patterns. |
| GOV.UK - 2024 holiday reforms | The 12.07% accrual method and rolled-up holiday pay rules. |
| ACAS - Checking holiday entitlement | Practical guidance on the days × 5.6 formula and rounding rules. |
| ACAS - Irregular-hours and part-year workers | The post-2024 accrual rules with worked examples. |
| ACAS - Part-time workers | Less favourable treatment, comparators, and pro-rata principles. |
| Part-time Workers Regulations 2000 | The legislation prohibiting less favourable treatment. |
| Working Time Regulations 1998 | The statutory framework for paid annual leave. |
| nidirect - Northern Ireland | Holiday rules and the 10 NI bank holidays. |
Frequently asked questions
The questions UK employers and staff ask most often about part-time holiday entitlement.
How many days holiday for someone working 3 days a week in the UK?
A 3-day-a-week worker is entitled to 16.8 days of statutory paid holiday per year (3 × 5.6 weeks). Employers must round part days up, especially during the first year of employment, per ACAS guidance.
Do part-time workers get bank holidays in the UK?
There is no automatic right to bank holidays - it depends entirely on the employment contract. If full-timers receive bank holidays in addition to annual leave, part-timers must get a pro-rata share of the bank holiday allowance to avoid less favourable treatment under the Part-time Workers Regulations 2000.
What is the difference between a part-time worker and an irregular hours worker?
A part-time worker has a fixed pattern (e.g., always 3 days a week) and uses the days × 5.6 formula. An irregular hours worker has wholly or mostly variable hours each pay period (e.g., zero-hours or casual contracts) and accrues holiday at 12.07% of hours worked under the post-April 2024 Working Time Regulations.
How do I calculate holiday for someone working 30 hours a week?
Multiply the weekly hours by 5.6 weeks: 30 × 5.6 = 168 hours of paid annual leave per year. When the worker takes leave, deduct the actual hours they would have worked that day from the balance - this avoids the bank-holiday-Monday problem that catches out employers who calculate in days.
Do part-time workers get the same enhanced contractual leave as full-timers?
Yes. If you offer full-timers more than the statutory 5.6 weeks (e.g., 25 days plus bank holidays), part-timers must receive the same enhanced amount on a pro-rata basis. Treating them differently would breach the Part-time Workers (Prevention of Less Favourable Treatment) Regulations 2000.