Free tool

Zero-hours 12-week average pay calculator

Work out the correct holiday pay for irregular-hours and zero-hours staff using the statutory 12-week averaging method — the rate you are legally required to use since April 2024.

Enter up to 12 recent working weeks (skip weeks with no pay — they are excluded from the average under UK law). Weeks with incomplete data are ignored.

Gross pay (£)Hours worked

Enter at least one week's pay and hours to see the average.

Based on Employment Rights Act 1996 s.224 and the 2024 Working Time Regulations reforms. The 12-week look-back excludes weeks with no remuneration. If the worker has been employed for fewer than 12 weeks, use however many full weeks are available (up to 52). Overtime, commission and some allowances may need to be included — check GOV.UK for your situation. WagePilot calculates average pay and holiday balances automatically for irregular-hours staff.

Holiday pay for zero-hours workers: the law

Since April 2024, the rules for paying holiday to irregular-hours and part-year workers have been settled following years of case law and two rounds of reforms:

12-week average look-back — when a zero-hours or irregular-hours worker takes annual leave, their holiday pay must equal average weekly pay calculated from the 12 working weeks immediately before the leave. Weeks with no pay are ignored and you count back further, up to a 52-week maximum.
What "pay" includes — regular gross pay, regular overtime and regular commission that forms part of normal remuneration. One-off bonuses and pure expense reimbursements are excluded.
Alternative: rolled-up holiday pay — for irregular-hours and part-year workers you may instead pay 12.07% of pay on top of each payslip as holiday pay is earned. This must be itemised on the payslip and paid in the same period as the work.
The Harpur Trust v Brazel rule no longer applies — the Supreme Court ruling that holiday pay could not be pro-rated was effectively overridden by the 2024 regulations, removing the anomaly that gave part-year workers disproportionately high leave pay.

Getting this wrong exposes you to holiday pay claims at employment tribunal. WagePilot stores hours and pay data week by week for every irregular-hours worker, so when leave is taken the 12-week average is calculated automatically — no spreadsheet required.

Holiday pay questions

How is holiday pay calculated for zero-hours workers?

Under the 2024 Working Time Regulations reforms, holiday pay for irregular-hours and part-year workers is based on average pay over the 12 working weeks immediately before the leave begins. Any week in which no pay was received is excluded, so you look back further until you have 12 paid weeks (up to 52 weeks maximum).

What counts as "pay" in the 12-week average?

Gross regular pay, overtime (where it is worked regularly), commission (where it forms part of normal remuneration), and some contractual bonuses. Pure expenses reimbursements and one-off discretionary bonuses are generally excluded. Check GOV.UK or a specialist adviser for your specific situation.

What if a worker has been employed for fewer than 12 weeks?

Use however many full working weeks the worker has been employed, up to a maximum of 52. If they have only worked 4 weeks, average over those 4 weeks.

Is the 12-week averaging rule new?

The 12-week averaging method (with a 52-week look-back) for irregular-hours and part-year workers was confirmed for leave years starting on or after 1 April 2024, following the Supreme Court's Harpur Trust v Brazel ruling. Before that ruling, many employers incorrectly used the 12.07% method for all workers.

Can I pay 12.07% of all pay as holiday pay instead?

The 12.07% rolled-up holiday pay method is now only permitted for irregular-hours and part-year workers under the 2024 reforms, and only if it is calculated and paid in the same pay period as the work (not accumulated). The 12-week averaging method remains an alternative.

Does this apply to agency workers?

Agency workers who work irregular hours are also covered by the 12-week averaging rules. The agency is typically the employer for holiday pay purposes. Check the specific arrangements in your agency supply contract.

WagePilot calculates the 12-week average for you

Holiday balances, correct pay rates and approval workflows — all automatic, for every worker type, from £10 a month per site.

Start my free trial See the live demo — no sign-up

Free forever on one site · no card to start · 14-day trial on paid plans · cancel anytime