Hourly wage

Your rate times your hours times the weeks you are paid gives a gross salary, and from there this is the take-home pay calculator — the same engine, so the two cannot disagree.

⚠ Fifty-two weeks is an assumption, and for a lot of jobs it is wrong

Term-time-only contracts, fixed agency bookings and seasonal work are paid for the weeks actually worked. Assuming a full year overstates the salary by exactly the weeks that are missing, and overstates the tax with it — a term-time job at £15 an hour is not the same tax position as a year-round one at £15 an hour. Change the weeks figure and everything below it moves.

What an hour is worth is not your rate

The row at the bottom divides your take-home by the hours you actually worked. It is always lower than your rate, and how much lower depends on where your pay sits: the first hours of the year are covered by your Personal Allowance and cost nothing, and later ones are taxed at 20%, 40% or more. That is why an extra pound an hour is never an extra pound in your pocket, and why the gap widens as you earn more.

⚠ Being paid weekly changes your National Insurance

National Insurance is worked out afresh on every pay packet, against a threshold for that period. This calculator assumes you are paid monthly and evenly. If your hours swing about — a quiet week and then a heavy one — the real National Insurance is higher than an even split suggests, because the busy period is charged on its own and the quiet one cannot lend it any unused threshold. The same is true of student loan repayments.

What this does not cover

Overtime paid at a premium (add the extra hours at your basic rate for an approximation, or use your actual expected annual pay on the take-home page), unsocial-hours enhancements, holiday pay rolled into the rate, a rate that changes part-way through the year, benefits in kind, or a second job — for which there is a separate calculator, because National Insurance is charged on each employment separately.

If you want to check a rate against the legal minimum rather than work out take-home pay, use the minimum wage calculator.

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.