What Actually Leaves Your Payslip
A UK salary is reduced by two separate deductions that behave differently. Income tax is charged in bands above a personal allowance; National Insurance has its own thresholds and its rate falls rather than rises at the top. Adding them together as a single "tax rate" is why the take-home figure surprises people.
This calculator separates them, showing income tax and National Insurance against your gross salary along with the effective rate you actually pay.
How to Work Out Your Take-Home Pay
Two inputs cover most cases, and the tax code is the one that changes the answer.
- Enter your annual gross salary, before any deductions.
- Enter your tax code if it is not the standard one. The number in the code times ten is your personal allowance, so 1257L means £12,570 tax free.
- Read income tax and National Insurance separately. They use different thresholds, so neither is a fixed share of the other.
- Check the effective rate, which is total deductions over gross. It is always lower than your marginal band, because the bands below it are charged at lower rates.
- Note that pension contributions, student loan repayments and salary sacrifice are not included here and will reduce your take-home further.
The 60% Trap Between £100,000 and £125,140
The personal allowance is withdrawn by £1 for every £2 of income above £100,000, which means an extra pound of salary in that band both attracts 40% tax and removes 50p of allowance that then gets taxed at 40% too. The effective marginal rate over that stretch is 60%, higher than the 45% additional rate that applies above it.
The allowance is fully gone at £125,140, which is where the additional rate begins. Anyone whose salary lands inside that band is in the most heavily taxed stretch of the UK system, and it is the reason pension contributions or salary sacrifice are so often recommended to bring taxable income back below £100,000.
Income Tax and National Insurance Bands
The rates this calculator applies, for an employee on the standard personal allowance.
| Band | Income tax | National Insurance |
|---|---|---|
| Up to £12,570 | 0% | 0% |
| £12,570 – £50,270 | 20% | 8% |
| £50,270 – £100,000 | 40% | 2% |
| £100,000 – £125,140 | 40% plus allowance taper | 2% |
| Above £125,140 | 45% | 2% |
National Insurance falls to 2% above £50,270 rather than rising, which is why the combined marginal rate at £50,270 jumps from 28% to 42% rather than to 48%. Scotland sets its own income tax bands and rates, and this calculator uses the rest-of-UK figures.
What This Calculator Does Not Include
The figures cover income tax and Class 1 employee National Insurance only. Workplace pension contributions, student loan repayments under any plan, the High Income Child Benefit Charge and salary sacrifice arrangements all change take-home pay and none of them appear here.
This is an estimate for general guidance rather than a payroll calculation or tax advice. Scottish taxpayers face different bands, and anyone with multiple employments, benefits in kind, or self-assessment income has a position this cannot represent. HMRC’s own tools or an accountant are the right source where the number matters.
It is also worth knowing that PAYE is cumulative across the tax year. Each payslip recalculates the tax due to date rather than treating the month in isolation, which is why a bonus month is taxed heavily and a later month may correct it. A code that is wrong early in the year usually resolves itself through this mechanism, though a code left wrong to the end requires a claim to put right.