Required salary
2026-27How this is worked out
This is the take-home pay calculator run backwards. There is no separate formula: the same engine is asked what a salary leaves you with, over and over, until it finds the smallest gross salary that reaches your figure. So the two pages cannot disagree — if one is right, so is the other.
Why it is searched rather than solved
Take-home pay is not a formula you can rearrange. It is a ladder of tax bands, a National Insurance calculation done afresh on every month's pay, a student loan repayment rounded down to whole pounds twelve separate times, and a Personal Allowance that tapers away above £100,000. Writing the inverse by hand would mean restating all of that a second time and keeping both copies right for ever.
Searching works because take-home is monotonic: no band, threshold or taper in UK tax ever takes more than the whole of an extra pound, so earning more always leaves you with more. That is what makes it safe to narrow in on the answer.
It answers in the period you asked in
A monthly take-home figure is the annual one divided by twelve and rounded to the penny, so the salary that gives you exactly £2,500 a month is not quite the salary that gives you £30,000 a year — it is a few pence lower. Ask in months and the answer is measured in months.
What this does not cover
The same things the take-home calculator leaves out: it assumes you are paid monthly and evenly across the year, and it does not handle Blind Person's Allowance, Marriage Allowance, benefits in kind, a bonus, or the higher-rate relief a higher-rate taxpayer claims back on a relief-at-source pension. A gross salary is also not the whole cost to an employer, which carries employer National Insurance and pension on top.
Where these rates come from
Every figure above is read from a dated rate file rather than written into the page, and each entry records the gov.uk page it came from. See Income Tax rates and Personal Allowances, Scottish Income Tax and rates and thresholds for employers on gov.uk. How these numbers are kept right sets out the whole process.