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UK Pro-Rata Tool (Updated 2026)

UK Holiday Accrual Calculator (Pro Rata)

Leaving a job or working irregular hours? Calculate your exact holiday entitlement and remaining balance for final pay.
Statutory minimum is 28 days for full-time. Include bank holidays if your contract does.
End date must be after start date.
Total Accrued (Earned)
0.0 Days
- Days Taken
0.0 Days
Remaining Balance Owed
0.0
Days
Standard Pro-Rata: This calculates the proportion of the year worked (Days / 365 * Allowance) minus the days you've taken. If the balance is negative, you owe your employer money.

How to Calculate Pro Rata Holiday Entitlement (The 365-Day Formula)

If you work a standard full calendar year at a UK company, calculating your holiday is easy—you simply get your full contractual allowance. However, if you join a company part-way through the year or hand in your notice to leave, you are only entitled to a pro rata portion of that leave.

For standard salaried employees, HR departments use a precise 365-day calculation to ensure you get paid exactly what you have earned up to your final working day. The formula is:

(Days worked ÷ 365) × Total Annual Holiday Allowance = Gross Accrued Holiday

Example Use Case: Sarah gets 28 days a year. Her leave year starts Jan 1st. She leaves exactly 6 months into the year (approx 182.5 days) and has already taken 5 days off. Her Gross Accrued is 14 days. Subtracting the 5 days taken, her final balance owed is 9 days.

UK Statutory Minimum Holiday Entitlement (Full Year)
Days Worked Per Week Statutory Annual Holiday (Days) Includes Bank Holidays?
5 Days (Full-time) 28 Days Yes (Employer decides if they count towards the 28)
4 Days (Part-time) 22.4 Days Pro-rata applied
3 Days (Part-time) 16.8 Days Pro-rata applied
Irregular Hours Calculated at 12.07% Accrued as you work

Resigning or Fired? Calculating Your Final Holiday Pay (Payment in Lieu)

If you are leaving your job, the "Remaining Balance Owed" produced by the calculator above is critical. By law, your employer must compensate you for any accrued statutory annual leave that you have not taken by your final day.

This is known in the UK as "Payment in lieu of holiday". It must be included in your final payslip. Conversely, if your balance is negative (meaning you have taken more holiday than you have accrued by your leave date), your employer is legally allowed to deduct the overpaid amount from your final wage.

A clean, professional close-up of a UK employee's final payslip. A row labeled 'Holiday Pay (Payment in lieu)' shows a positive monetary value. A green checkmark points to it, indicating the employee was correctly paid for their unused accrued holiday balance upon resignation.
Payment in lieu of holiday ensures you are financially compensated for every day of annual leave you earned but did not take before your contract ended.

The 12.07% Rule for Part-Time & Irregular Hours

Following updates to the UK Employment Rights Regulations (specifically affecting holiday years starting on or after April 1, 2024), the way holiday is calculated for irregular hours workers and part-year workers has been clarified.

Instead of the 365-day pro-rata method, these workers accrue holiday at a rate of 12.07% of the hours they have actually worked in a pay period. Why 12.07%? Because standard statutory leave is 5.6 weeks a year, leaving 46.4 working weeks (5.6 ÷ 46.4 = 12.07%). If your shifts vary week by week, you can use our weekly hours calculator to sum up your total hours worked before applying the 12.07% rule in the tool above.

Frequently Asked Questions

1. How do you calculate accrued holiday pay for leavers?

You calculate the proportion of the leave year the employee has worked (days worked divided by 365), and multiply that by their total annual holiday entitlement. Finally, subtract any holiday days they have already taken to find the remaining balance owed.

2. What is payment in lieu of holiday?

Payment in lieu of holiday is the financial compensation an employer must pay an employee for any accrued statutory annual leave that they have built up but not taken by their final day of employment.

3. Do I accrue bank holidays while on maternity leave?

Yes. In the UK, your statutory annual leave (including bank holidays, if they are part of your contractual entitlement) continues to accrue exactly as normal while you are on statutory maternity, paternity, or adoption leave.

4. What is the 12.07% holiday rule?

The 12.07% rule is the standard calculation method used in the UK for zero-hour or irregular hours workers. Because statutory leave is 5.6 weeks a year out of 46.4 working weeks (5.6 / 46.4 = 12.07%), holiday accrues at 12.07% of the hours actually worked.

Official UK Resources & Guidelines