Hundred SummersBonus tax calculator: what you actually keep
No special bonus rate exists: a bonus is income stacked on top of your salary. This calculator differences the real band, NI and student-loan functions at salary versus salary-plus-bonus, so band crossings and the £100k taper price themselves. Your figures never leave your browser.
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Worked example
Computed when this page was built by the same engine that runs the calculator above, so the figures below and the live tool can never disagree. Change any input above to see your own.
| Inputs | |
|---|---|
| Salary | £55,000 |
| Bonus | £10,000 |
| Scottish taxpayer | No |
| Student loan | None |
| Results | |
|---|---|
| Tax and NI taken from the bonus | £4,200 |
| Bonus you keep | £5,800 |
| Kept | 58% |
| Lost | 42% |
The next question
Would sacrificing the bonus into a pension save tax? →Salary sacrifice calculator
Or answer it with everything else: the full Hundred Summers plan connects your pay, pensions, savings, property, tax and spending year by year, and stress-tests them across 500 simulated market histories.
Read the guide
- Bonuses: why so much disappears, and the move that keeps it →A bonus is taxed as the top slice of the year's pay, so it lands at your highest rate plus NI (42% gone for a higher-rate earner, more in the 60% zone), and a bonus sacrificed into a pension is the best-relieved contribution most employees ever make.
Why bonuses feel over-taxed
A bonus lands on top of your other income, so it's taxed entirely at your marginal rates, often a band above what your salary suggests, sometimes two. Crossing £100,000 is the sharp edge: the personal-allowance taper takes the effective rate to 60% (62% with NI) until £125,140. Payroll also sometimes over-withholds in the bonus month and corrects later: the annual arithmetic here is what you truly keep.
Bonus sacrifice is the counter-move: waived into your pension before payment, a bonus escapes income tax and NI entirely; the salary sacrifice calculator prices it exactly. The full Hundred Summers plan models bonuses (and their probability) across your whole projection.