Guide
How Is a Pro Rata Bonus Worked Out in the UK?
A part-year bonus may be reduced when you join or leave during the bonus period. The arithmetic is straightforward, but the written scheme determines whether a payment is due. Use the pro rata bonus calculator for a day-based estimate.
Day-based calculation
full bonus × eligible calendar days ÷ calendar days in the bonus period
A £10,000 bonus with 182 eligible days in a 365-day period gives an estimate of £4,986.30 before payroll deductions.
Month-based calculation
Some schemes use complete eligible months divided by the months in the period. That can differ from a day-based result when employment starts or ends partway through a month.
Scheme rules come first
Check the bonus period, eligibility date, performance conditions and leaver terms. A discretionary or conditional scheme may reduce or remove a payment even when the pro rata arithmetic produces a figure. Cash bonuses paid through payroll are normally subject to Income Tax and National Insurance.
▲ Check your own figure
Plug your numbers into the pro rata bonus calculator — it shows the full working, so you can see exactly which days were counted.