The salary calculator turns a headline salary into the number that actually matters: what lands in your bank account. Enter your annual gross pay, choose your tax region, and add any workplace pension percentage or student loan plan you're on, and it works out income tax, employee National Insurance, pension contributions and student loan repayments in one pass. It's built for anyone comparing job offers, checking a payslip, or simply working out what a raise is actually worth once everything has been taken off.

Two deductions do almost all of the work: income tax and National Insurance. Income tax is worked out on your taxable income, which is your gross pay minus your tax-free Personal Allowance of £12,570 for 2026/27 (assuming you earn under £100,000 - more on that below). Whatever is left after the Personal Allowance is taxed in slices, or bands, at increasing rates - so a pay rise never pushes your whole salary into a higher rate, only the portion that falls above the threshold.

National Insurance is calculated separately, straight from your gross earnings rather than your taxable income. For 2026/27, employees pay 8% on everything between £12,570 and £50,270 a year, then 2% on anything above £50,270. Unlike tax, NI doesn't care about your Personal Allowance directly - it has its own threshold, which for most employees happens to sit at the same £12,570.

Take a salary of £45,000 in England, Wales or Northern Ireland, with no pension or student loan. The first £12,570 is tax-free, leaving £32,430 of taxable income, all of which sits inside the 20% basic-rate band. That's £6,486 of income tax. National Insurance is charged on the same £32,430 (the amount above the £12,570 threshold) at 8%, which comes to £2,594.40. Total deductions come to £9,080.40, leaving take-home pay of £35,919.60 a year - about £2,993 a month.

A few things can throw the numbers off if you're comparing against a real payslip. If your tax code isn't the standard 1257L - for example because you're repaying an underpayment, receiving a taxable benefit like a company car, or have a second job - your actual tax-free amount will differ. A workplace pension taken as a percentage before tax (a 'net pay arrangement') lowers your taxable income but leaves your NI band unaffected, whereas salary sacrifice schemes lower your gross pay for both tax and NI, which usually means a slightly bigger saving.

Bonuses, overtime and commission should be added to your gross salary before you calculate, since they're taxed exactly like the rest of your pay in the month they're received - even though a large one-off bonus can look like it's taxed at an unfairly high rate on the payslip itself, because the PAYE system assumes that month's pay is your regular monthly amount.

The results are broken down by year, month, four-weekly, weekly and daily pay, so you can line up a salary against rent, a mortgage or weekly outgoings without doing the division yourself. If you're in Scotland, switch the tax region setting - Scottish income tax uses six bands from 19% to 48% instead of the three used elsewhere in the UK, and the calculator applies them automatically.