£100k tax trap calculator
Is the trap 60%, 62% or 71%? All three are quoted by authoritative sources, and none is wrong: they just count different deductions. 60% is income tax alone, 62% adds the 2% National Insurance, and a Plan 2 student loan takes it past 70%. Rather than pick a headline, this calculator computes the tax on one more pound of your income and reports the rate you actually face.
Calculator
£100k tax trap calculator
Your exact marginal rate at £115,000
62.0%
Of the next £100 you earn, £38.00 reaches your pocket. We measure this by actually computing the tax on £1 more, not by quoting a headline figure.
The marginal rate, salary by salary
| Salary | Marginal rate | Next £100 is worth |
|---|---|---|
| £95,000 | 42.0% | £58.00 |
| £100,000 | 62.0% | £38.00 |
| £105,000 | 62.0% | £38.00 |
| £115,000 | 62.0% | £38.00 |
| £125,140 | 47.0% | £53.00 |
| £130,000 | 47.0% | £53.00 |
Check what the same income does to childcare and Child Benefit →
The trap, drawn
Quoted as a number the £100k trap invites an argument about which percentage is right. Plotted, the argument goes away: there is a spike between £100,000 and £125,140 that is visibly taller than the additional rate to its right.
| Salary | England, Wales & NI | Scotland |
|---|---|---|
| £20,000 | 28.0% | 28.0% |
| £40,000 | 28.0% | 29.0% |
| £50,000 | 28.0% | 50% |
| £60,000 | 42.0% | 44.0% |
| £99,000 | 42.0% | 47.0% |
| £110,000 | 62.0% | 69.5% |
| £125,000 | 62.0% | 69.5% |
| £130,000 | 47.0% | 50.0% |
| £160,000 | 47.0% | 50.0% |
Why does the £100k tax trap exist?
Above £100,000 of adjusted net income the personal allowance is withdrawn at £1 for every £2 earned. Each extra pound is therefore taxed at 40% and pulls 50p of previously tax-free income into 40% tax, 60% combined, before National Insurance. The taper ends at £125,140, where the allowance is exhausted and the marginal rate falls back to 47%, making this the only place in the UK system where earning more is taxed above the additional rate itself.
Why losing childcare at £100,000 costs more than the tax
The same £100,000 line is a cliff edge for childcare, and it behaves differently from the tax. The taper is gradual; this is not. One pound of adjusted net income over the line forfeits the funded hours and Tax-Free Childcare outright, for the whole household, and it is re-confirmed every three months. For a family with two children in nursery the loss can exceed £5,000 a year, which means a £1 pay rise can leave you thousands of pounds worse off. The escape route for both the tax and the cliff is the same: salary sacrifice or a pension contribution that brings adjusted net income back under the line. The childcare cliff calculator prices both losses together and solves for the contribution that avoids them.
What does the trap cost in total?
Crossing the whole taper, earning £125,140 instead of £100,000, means £25,140 of extra gross pay of which roughly £15,587 goes in tax and National Insurance at the 62% effective rate: you keep about £9,553. That is why salaries between £100,000 and £125,140 are where large pension contributions make the most arithmetic sense in the UK, the taper means the state funds most of them. The withdrawal itself follows from the personal allowance rules on gov.uk's “Income over £100,000” guidance, and the thresholds are on our rates reference with their HMRC sources.
Common questions
Is the £100k tax trap 60%, 62% or 71%?
All three are quoted because they count different deductions. On £110,000 in England the income tax alone is 60%, because each extra pound is taxed at 40% and also withdraws 50p of personal allowance that is then taxed at 40% too. Add 2% National Insurance and the real marginal rate is 62.0%. Add a Plan 2 student loan and it reaches 71.0%. In Scotland it is 69.5%, because £100,000 falls inside the 45% advanced band. This page measures your own figure rather than quoting one.
Where does the £100k tax trap start and end?
It runs from £100,000 to £125,140 of adjusted net income. The personal allowance falls by £1 for every £2 earned above £100,000, so it is exhausted at £125,140. Above that the marginal rate falls back to 47%, which makes this the only band in the UK system taxed above the additional rate itself.
How much does crossing the whole taper cost?
Earning £125,140 instead of £100,000 leaves you £9,553 better off after tax, from £25,140 more gross. The rest goes in tax and National Insurance. On £110,000 specifically, take-home is £72,357 against £68,557 at £100,000.
Can I avoid the £100k tax trap?
Yes, and it is the one place where a pension contribution pays for itself fastest. A contribution made by salary sacrifice reduces the adjusted net income the taper is measured against, so bringing yourself back under £100,000 recovers the whole allowance. In this band each £100 into a pension costs roughly £38.00 of take-home pay. Relief at source lowers adjusted net income too but saves no National Insurance, so it costs more for the same result.
Does the £100,000 line affect anything other than tax?
Yes, and for parents it usually costs more than the tax does. Tax-Free Childcare and the funded childcare hours both stop if either parent's adjusted net income exceeds £100,000. That is a cliff, not a taper: one pound over the line ends both for the whole household, and it is re-confirmed every three months. For a family with two children in nursery the loss can exceed £5,000 a year.
2026/27 rates, checked 28 August 2026 by Hadi. The marginal rate is measured by computation, not quoted, the engine and its test anchors are described on the about page.
How to use the £100k tax trap calculator
- 1
Enter your salary and any other taxable income.
- 2
Add your pension contributions, which are the main way out of the trap.
- 3
Read the effective marginal rate on your next pound, which reaches 62% inside the taper.
- 4
See the contribution that would bring you back under £100,000.
When should you use the £100k tax trap calculator?
Use it if your income is anywhere near £100,000, since the marginal rate in that band reaches 62% and is higher again in Scotland.
You earn between £100,000 and £125,140
Your personal allowance is withdrawn £1 for every £2, so each extra pound is taxed at 62%.
You have a bonus that crosses £100,000
The bonus is the most expensive money you will earn all year.
You have children under 12
Crossing £100,000 also ends free childcare hours and Tax-Free Childcare, on top of the tax.
You live in Scotland
The Scottish bands make the same trap worse, around 69.5% rather than 62%.
Where to go next
- Adjusted net income calculatorTo work out the figure the taper is measured on.Open
- Pension sweet spot calculatorTo find the contribution that clears the taper.Open
- Childcare cliff calculatorTo the childcare loss that sits on the same threshold.Open
All 51 calculators share one tested engine, so a figure from the £100k tax trap calculator agrees with every other page here. See the full calculator index or the pay and tax guides.