About
This is a calculator for one question: what is the next £1 you earn actually taxed at? Not the headline rate — the real one, once the personal allowance withdrawal, National Insurance, student loan repayments and the Child Benefit charge have all been counted together.
Why the answer is not the headline rate
The rate on your payslip is not the rate on your next pound. Several rules overlap, none of them mentions the others, and between about £50,000 and £126,000 they stack up in ways that produce rates you will not find in any table of tax bands.
Above £100,000 the personal allowance is withdrawn at £1 for every £2 earned, so each extra pound is taxed twice over — once directly, and again by the allowance it takes away. The calculator draws the resulting band; it is not a rate that appears in any table of tax bands, and it is the reason this page exists. Between £60,000 and £80,000 the High Income Child Benefit Charge claws back a benefit you may not realise is being clawed back. And at exactly £100,000 of adjusted net income, Tax-Free Childcare and the funded hours disappear altogether — not tapered, gone, for both parents and every child, on the strength of one pound.
Each of those is knowable. Together they are hard to hold in your head, and nothing in the ordinary run of payslips and P60s shows them to you.
How it works
The page is a static file. There is no server, no account and no database. The tax engine runs in your browser tab, on your device, and computes everything from the figures you type — which is why nothing you enter is ever transmitted anywhere, and why there is no cookie banner: there is nothing to consent to. The privacy page sets that out in full.
The link in your address bar carries your figures, so you can share a result or come back to it. That happens entirely in the browser; the address is never sent to us, because there is no us to send it to.
Where the figures come from
Every rate and threshold is a cited parameter carrying the gov.uk page it came from and the date a person last checked it. The default year here is 2026/27, last checked on 29 August 2026.
Nothing is estimated, averaged or remembered. Where a figure is needed and has not been verified, this calculator says so and declines to compute rather than showing a plausible number — the childcare funding rate is the clearest example, because it varies by council and by the child’s age, so the page asks for yours instead of inventing a national one.
What it will not do
It will not tell you what to do. It reports what a set of figures produces under the rules, and stops there. It does not rank your options, does not single one out, and will never suggest a course of action — not as a limitation of the current version, but as a deliberate boundary that keeps this an information tool rather than regulated advice.
It also names no provider, product or fund anywhere. No link on this page earns anyone a commission, no placement on it has been paid for, and there is nothing being sold.
Nomogram is not authorised or regulated by the Financial Conduct Authority and does not carry on any regulated activity. Nothing here is a personal recommendation. Before taking, or refraining from taking, any action you should obtain advice from a professional authorised to give it — and free impartial guidance is available from MoneyHelper. The disclaimer and terms have the rest.
Why “nomogram”
A nomogram is a graphical calculator: parallel scales arranged so that a straightedge laid across two known values reads the answer off a third. They were how engineers computed before calculators were pocket-sized, and they are still the clearest way to show a relationship between three quantities at once.
The chart at the top of this page is a working one, not a decoration. Lay the line from your salary through your pension sacrifice and it crosses the middle scale at your marginal rate. The mark in the corner is the same figure, reduced to three rules and a diagonal.