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TaxCliff

The UK tax calculators that show their working

Most calculators tell you what your take-home pay is. These tell you why it is that number, and where the rules that produced it are published.

£

You keep

£28,720

£2,393 a month

Your next £1 is worth

72p

28.0% of a pay rise goes in tax and National Insurance

See the full workingSee the 62% trap

One salary, no pension, no student loan, the standard tax code. The full calculator asks about all of those — this link carries your figure over to it.

The rates nobody publishes

HMRC publishes 20%, 40% and 45%. None of those is the rate most people actually pay on their next pound. These are, for 2026-27, calculated by this site's engine:

62%

£100,000 to £125,140

England, Wales and Northern Ireland. The Personal Allowance is withdrawn as you earn, so each extra pound is taxed twice over.

69.5%

The same band, in Scotland

The advanced rate is 45% rather than 40%, so the same withdrawal costs considerably more.

47%

Above £125,140

The rate goes down once the allowance is gone — which is why a pay rise through this band can be worth less than one above it.

Start with your question

Every one of these runs on the same engine and shows the same working. They differ only in the question they are built to answer.

And where a calculator is the wrong shape for the question, there are guides: What does my tax code mean, What is salary sacrifice, and is it worth it, and What counts as my adjusted net income.

Three things these calculators get right

How your pension is paid changes the answer
Salary sacrifice, net pay and relief at source produce three different take-home figures for the same contribution — and only one of them also cuts your student loan repayment. Most calculators offer a single pension box.
Scotland is not a footnote
Six bands, not three, and they apply to earned income only — savings and dividends are still taxed at the rest-of-UK rates.
Every number links to its source
Open the working under any result: each step names the rule it applied, and every step that rests on a published figure links the gov.uk page that figure was read from. See methodology for the full table.

Questions people arrive with

How much tax will I pay on my salary?
Income tax at 20%, 40% and 45% depending on the band your income falls in, plus National Insurance on everything above £12,570. The published rates are only half the answer: what the next pound of a pay rise is actually worth depends on where you are standing, and between £100,000 and £125,140 that figure is 62% rather than any rate in the table.
Why is my take-home pay lower than a calculator said?
Usually one of four things: a tax code that is not the standard one, a student loan the calculator did not ask about, a benefit in kind such as a company car being taxed through your code, or a bonus paid in a month that pushed that month into a higher band. Every calculator here shows its working line by line, so you can find which one it is rather than guessing.
Do these calculators work for Scotland?
Yes, and the difference is not only the rates. Scotland sets its own bands for earned income — 6 of them against 3 in the rest of the UK — while savings, dividends and capital gains stay on rest-of-UK rates and rest-of-UK boundaries even for a Scottish taxpayer. That second half is the part most calculators get wrong.
Where do the figures come from?
gov.uk, gov.scot and legislation.gov.uk, and every one of them carries the sentence it was read from. Nothing on this site is typed in from memory: the rates live in a data layer, the pages read them, and the build fails if a figure appears in a page that the data layer does not set.
Is it free, and do I have to sign up?
Free, and there is nothing to sign up to. Nothing you type is sent anywhere — the calculators run entirely in your browser, which is also why a shared link carries your figures in the address bar rather than on a server.

Why you should believe any of it

Because none of it is typed by hand. Every rate and threshold is read from a published page, quoted alongside the figure it produced, and the build fails if a page states a tax figure that did not come from that data — the check mutates every number the site holds, rebuilds, and looks for survivors. It is a proof rather than a promise.

Where a figure could not be confirmed against a page carrying the right year's label, it is named as unconfirmed rather than quietly used. Where a rule is not modelled, each calculator says so in its own words. Every figure and its source is published, along with what could not be confirmed; every change is dated; and the person behind it is named, including the review that has not happened.