Annual leave is paid time off that every UK employee is legally entitled to each year. Under the Working Time Regulations 1998 (WTR), the statutory minimum is 5.6 weeks per year — but calculating exactly how many days or hours that means for each employee requires working through a straightforward formula. Get the maths wrong and you risk under-allocating leave (a legal complaint) or over-allocating it (an unwelcome cost).

This guide walks you through how to calculate annual leave entitlement in the UK, step by step, including full-year employees, part-year workers, and those starting or leaving mid-year.

Key Takeaways

  • UK statutory minimum annual leave is 5.6 weeks (28 days for a 5-day worker), under Working Time Regulations 1998, regulation 13.
  • Employers can include bank holidays within the 5.6-week entitlement.
  • Full-time employees working 5 or 6 days per week get 28 days (or 33.6 including bank holidays).
  • Part-year and irregular-hours workers accrue leave at 12.07% of hours worked in each pay period.
  • Leave accrued but not taken carries over under specific rules, and employers must not discourage workers from taking it.

Step 1: Determine the statutory entitlement

The foundation is regulation 13 of the WTR: every worker is entitled to 5.6 weeks of paid annual leave per leave year. The leave year is usually stated in the employment contract — it could run January to December, April to April, or any other 12-month period the employer sets.

For a full-time worker on a standard five-day week, that means:

  • 5 days × 5.6 = 28 days

If the employee works six days per week, it becomes 33.6 days. Employers typically round to the nearest whole day.

Bank holidays inside the 28 days

The WTR allows employers to count the eight bank holidays and Christmas close-down days within the 5.6-week entitlement. If you do this, the employee effectively gets 20 days plus eight bank holidays. If you do not count them, the employee gets 28 days on top of bank holidays. The choice sits with the employer but must be stated in the contract.

Step 2: Work out the daily or hourly accrual rate

To convert weeks into days, divide the worker’s total contractual days in the leave year by the number of working days per week, then multiply by 5.6.

Formula:

Annual leave days = (total working days in leave year ÷ number of working days per week) × 5.6

For a five-day worker in a full year with no absences, this is simply 28 days.

For hourly calculation (useful for shift workers):

Annual leave hours = average weekly hours × 5.6

A worker averaging 30 hours per week gets 168 hours of annual leave.

Step 3: Handle part-year and irregular-hours workers

Part-year workers — those who only work part of the year — accrue leave differently. Following the 2024 amendments to the WTR implementing the 2023 holiday pay and entitlement reforms:

  • For irregular-hours and part-year workers, holiday entitlement is accrued at 12.07% of actual hours worked in each pay period.
  • The 12.07% figure comes from the fraction 5.6 weeks ÷ (52 weeks − 5.6 weeks) = 5.6 ÷ 46.4 = 12.07%.

So an irregular-hours worker who works 60 hours in a given pay period accrues 7.24 hours of leave for that period.

Step 4: Calculate leave for someone starting or leaving mid-year

When an employee starts or leaves partway through the leave year, you pro-rate their entitlement.

Starters:

Annual leave = (months remaining in leave year ÷ 12) × 28

Example: An employee starts on 1 July and the leave year runs January to December. Seven months remain: (7 ÷ 12) × 28 = 16.33 days.

Leavers:

Annual leave used = (months elapsed ÷ 12) × 28 − days already taken

If the employee has taken more days than they have accrued, you can deduct the overpayment from their final pay — but only if the contract explicitly permits it.

Step 5: Factor in carry-over rules

The WTR and case law from the Court of Justice of the European Union (now retained in UK law) set strict carry-over rules:

  • Employees must take at least four weeks (20 days) of their entitlement in the leave year it is accrued. This cannot carry over.
  • The additional 1.6 weeks (the UK’s extra above the EU minimum) can be carried over if the employer’s policy allows it.
  • If an employer fails to give reasonable opportunity to take leave, or fails to inform the employee they must take it, the carry-over limitation does not apply — the leave carries over until the employment ends.

The COVID-19 pandemic expanded carry-over rights temporarily, and some of those provisions have been codified permanently for specific circumstances.

Step 6: Check the contract against the statutory minimum

Many employers offer more than the statutory 28 days. Your contract might say “30 days plus bank holidays” or “25 days plus bank holidays” — these are contractual terms, not statutory rights. When an employee leaves, the statutory minimum still applies as the floor.

Where there is a discrepancy, the higher figure wins for what the employee actually receives, but for calculating pro-rata on departure, use whichever method is more favourable to the worker.

Common pitfalls in annual leave calculation

1. Forgetting irregular-hours workers

Many employers still apply the 5.6-week formula to zero-hours or variable-hours staff. Since 2024, the 12.07% accrual method is the correct approach for irregular-hours and part-year workers, and it produces different numbers.

2. Miscounting bank holidays in Scotland and Northern Ireland

Bank holiday entitlements differ across UK nations. Scotland has different bank holiday dates from England and Wales, and Northern Ireland has additional ones. Ensure your calculation reflects the actual bank holidays applicable to the employee’s work location.

3. Not accounting for the statutory minimum on termination

Even if a contract says 28 days including bank holidays, the statutory minimum on termination may differ if the employee has taken fewer bank holidays than exist in the leave year.

4. Including overtime in the accrual calculation

For workers with regular overtime, the accrual should be based on their normal weekly pay — which, since the 2024 reforms, includes regular overtime in the holiday pay calculation for all 5.6 weeks, not just the additional 1.6 weeks.

Putting it into practice

Five checks cover most annual leave calculations:

  1. Check the contract to confirm the leave year period and whether bank holidays are included in the total.
  2. Apply the 5.6-week formula for full-time workers, or the 12.07% accrual for irregular-hours and part-year workers.
  3. Pro-rate for anyone starting or leaving mid-year using the fraction of months remaining or elapsed.
  4. Verify the statutory minimum against the contractual entitlement before calculating on termination.
  5. Track leave in a system that automatically applies carry-over rules and flags unused entitlement before the end of the leave year.
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A leave management system that calculates accrual automatically, applies carry-over rules by default, and handles mid-year starters without manual spreadsheets makes annual leave calculation accurate and legally compliant.

Frequently Asked Questions

How many annual leave days are UK employees entitled to?

Every UK worker is entitled to at least 5.6 weeks of paid annual leave per year. For a standard five-day week, this is 28 days. Employers may include bank holidays within this entitlement.

Do bank holidays count towards annual leave?

Yes, employers can include bank holidays within the statutory 28-day entitlement. If they do, a five-day worker gets 20 days plus bank holidays. If not, they get 28 days on top of bank holidays. The approach must be in the contract.

How do you calculate annual leave for part-time workers?

Multiply the number of days they work per week by 5.6. A three-day-a-week worker gets 3 × 5.6 = 16.8 days, typically rounded to 17.

What about zero-hours or irregular-hours workers?

Since 2024, irregular-hours and part-year workers accrue leave at 12.07% of hours worked in each pay period, rather than receiving a fixed annual allocation.

Can unused leave carry over to next year?

The four-week statutory minimum (20 days) cannot carry over unless the employer prevented the employee from taking it. The additional 1.6 weeks can carry over if the employer’s policy permits it.

This article is general information, not legal advice.

Last updated: 26 July 2026.