Bonus tax calculator
There is no separate bonus tax rate in the UK. A bonus is ordinary pay stacked on top of your salary, so it is taxed at your marginal rate, 28% for a basic-rate taxpayer once NI is counted, 42% at higher rate, and over 60% inside the £100k taper.
Calculator
Bonus tax calculator
Of your £5,000 bonus, you keep
£3,600.00
£1,400.00 (28%) goes in tax and National Insurance, the bonus is taxed at your marginal rate, on top of everything you already earn.
Or sacrifice it into your pension
A bonus given up before it is paid never counts as salary, so it escapes income tax and National Insurance, and it lowers the income the £100,000 taper is measured against. Your employer has to agree it in advance.
- Cash in your pocket
- £3,600.00
- Into your pension
- £0.00
- Cost per £100 saved
- —
Sacrifice has to be agreed before the bonus is paid: it cannot be applied to money you have already received. See the salary sacrifice guide for what else it affects, including mortgage applications and statutory pay.
“My bonus was taxed at 50%!”, the payroll month illusion
PAYE spreads your allowance and bands evenly across the year. A bonus lands in one month, so that month's pay is taxed as if you earned it every month, which over-deducts in the bonus month and quietly corrects itself over the rest of the year. The annual figures above are the true position; the payslip shock is timing, not extra tax.
Ways to keep more of a bonus
- Bonus sacrifice: paid into your pension before tax and NI, so £100 of bonus becomes £100 of pension instead of £58-72 of cash. Most valuable inside the taper. See the salary sacrifice calculator.
- Timing: if a bonus would tip you over £100,000 of adjusted net income and you have young children, the childcare loss can exceed the bonus itself; a pension contribution restores it.
- Student loans: repayments are per pay period, so a bonus month triggers 9% on the excess even if your annual pay is near the threshold.
2026/27 rates, checked 28 August 2026 by Hadi. Annualised comparison, your bonus-month payslip will differ for the timing reason explained above. Method on the about page.
How to use the bonus tax calculator
- 1
Enter your normal salary and then the bonus you are expecting.
- 2
Choose whether the bonus is paid as cash or sacrificed into your pension.
- 3
Read what lands in your account and the effective rate the bonus was taxed at.
- 4
Compare the two routes, which is the whole point of the tool.
When should you use the bonus tax calculator?
Use it before a bonus is paid, particularly if it crosses a threshold or if you can choose to put it into your pension instead.
You have a bonus coming
It is taxed at your marginal rate, so the headline figure is never what arrives.
Your bonus pushes you over a threshold
A bonus that crosses £50,270 or £100,000 is taxed far harder than the rest of your pay.
You can put the bonus into your pension
Sacrificing it avoids income tax and both National Insurance contributions on the whole amount.
Your bonus month NI looked wrong
NI is worked out per pay period, so a bonus month can be charged at the lower rate above the upper limit.
Where to go next
- Salary sacrifice calculatorTo model putting the bonus into a pension instead.Open
- £100k tax trap calculatorTo if the bonus takes you past £100,000.Open
- Pay rise calculatorTo the same arithmetic for a permanent rise.Open
All 51 calculators share one tested engine, so a figure from the bonus tax calculator agrees with every other page here. See the full calculator index or the pay and tax guides.