Annual Leave Calculator UK

The 12.07% accrual rate applies to workers correctly classified as irregular-hours workers or part-year workers under Working Time Regulations 1998, reg.15B (inserted by the Employment Rights (Amendment, Revocation and Transitional Provision) Regulations 2023, SI 2023/1426), for leave years beginning on or after 1 April 2024 — Great Britain only. It is derived from 5.6 ÷ 46.4 = 0.1207. For every hour worked, you accrue 0.1207 hours of leave. This method must only be used for workers whose hours genuinely vary from week to week or who work for only part of the leave year — not for standard part-time or full-time employees.

Northern Ireland has not adopted this method. NI irregular-hours and part-year workers accrue 5.6 weeks' leave pro-rata, calculated using a 12-week pay reference period, following Harpur Trust v Brazel [2022] UKSC 21. Contact the Labour Relations Agency (lra.org.uk) for an NI-specific calculation.

Source: WTR 1998, reg.15B; gov.uk/holiday-entitlement-rights; lra.org.uk.

Holiday pay must reflect your normal pay. For workers with regular hours and no variable elements, holiday pay equals your normal weekly pay. For workers with irregular hours, variable pay, or overtime, holiday pay is calculated as an average of earnings over a 52-week reference period (or the actual service period if under 52 weeks) — this 52-week period applies in Great Britain only. This rule applies from April 2020 under the Employment Rights (Employment Particulars and Paid Annual Leave) (Amendment) Regulations 2018.

In Northern Ireland, the reference period is 12 weeks, not 52. Source: lra.org.uk/resources/information-note/holidays-and-holiday-pay-0.

In Great Britain, the Employment Rights (Amendment, Revocation and Transitional Provision) Regulations 2023, SI 2023/1426 introduced a new accrual-based method for irregular-hours workers and part-year workers, taking effect from 1 January 2024 (leave years beginning on or after 1 April 2024). It replaced the approach following the Harpur Trust v Brazel Supreme Court ruling. Under reg.15B, holiday accrues at 12.07% of hours worked in each pay period, and rolled-up holiday pay (paid with each wage payment) is permitted for these workers.

This change does not apply in Northern Ireland, where employment law is devolved. Northern Ireland made its own, narrower amendments (Working Time (Amendment) Regulations (Northern Ireland) 2023, SI 2023/223, in force 1 January 2024), covering leave carry-over and the definition of a week's pay — but not the 12.07% accrual method and not rolled-up holiday pay. NI irregular-hours and part-year workers continue to follow Harpur Trust v Brazel: 5.6 weeks pro-rata, calculated over a 12-week reference period.

Source: SI 2023/1426; SI 2023/223; gov.uk/holiday-entitlement-rights; lra.org.uk.

If you're a zero-hours or casual worker with genuinely variable hours, select "Irregular hours or part-year worker" in this calculator's working pattern options, rather than the standard fixed-hours calculation. This applies the 12.07% accrual method, designed for workers whose hours change from week to week or who work only part of the year.

Under the Working Time Regulations 1998, reg.15B (inserted by the Employment Rights (Amendment, Revocation and Transitional Provision) Regulations 2023, SI 2023/1426, with effect for leave years beginning on or after 1 April 2024), your holiday entitlement accrues at 12.07% of the hours you actually work in each pay period. Your employer can then pay you for that leave in one of two ways: as "rolled-up holiday pay" — an extra 12.07% added to your pay each pay period and itemised separately on your payslip — or as ordinary holiday pay, calculated from your average earnings, when you actually take leave.

This method must only be used if you're correctly classified as an irregular-hours or part-year worker. If you work fixed hours — even part-time — use the standard 5.6-weeks calculation instead.

This entire method — the 12.07% accrual and rolled-up holiday pay — applies in Great Britain only. Rolled-up holiday pay remains unlawful in Northern Ireland: NI employers must pay holiday pay when leave is actually taken, not rolled into your hourly rate. If you work in Northern Ireland, use the Labour Relations Agency's guidance instead: lra.org.uk.

Source: Working Time Regulations 1998, reg.15B; gov.uk/holiday-entitlement-rights; nibusinessinfo.co.uk; lra.org.uk.

For every hour you work as an irregular-hours or part-year worker, 0.1207 hours of paid holiday accrues — that's the 12.07% accrual rate applied directly to your hours. For example, a 20-hour week adds 2.41 hours (20 × 0.1207) of holiday entitlement for that week.

The 12.07% figure comes from dividing the statutory annual leave entitlement (5.6 weeks) by the number of working weeks left in the year once that leave is excluded (46.4 weeks): 5.6 ÷ 46.4 = 0.1207, or 12.07%. It applies only to workers correctly classified as irregular-hours or part-year workers under the Working Time Regulations 1998, reg.15B — Great Britain only — not to standard part-time or full-time employees, whose entitlement is calculated as a proportion of the 5.6-week statutory minimum instead, and not to Northern Ireland, where irregular-hours and part-year workers' entitlement is calculated differently (see "What changed for irregular-hours workers from 2024?" above).

Source: Working Time Regulations 1998, reg.15B; gov.uk/holiday-entitlement-rights.