Suppose you want £40,000 in your pocket for the 2026/27 tax year and need to know the salary to ask for. The tool searches for the gross that nets exactly that figure and lands on about £50,763. At that salary the personal allowance is still the full £12,570, so £38,193 is taxable: £37,700 at 20 percent plus a sliver at 40 percent gives income tax of roughly £7,737. Employee National Insurance adds about £3,026, charged at 8 percent between £12,570 and £50,270 with 2 percent on the small amount above. Subtract the £10,763 of combined deductions from £50,763 and you are left with the £40,000 target. On a monthly basis that is a gross of about £4,230.
How it is calculated
This is a reverse calculation, so there is no neat closed-form answer. Because income tax and National Insurance are banded, the gross needed for each extra pound of take-home rises as you cross the 40 percent threshold, the 60 percent personal-allowance taper between £100,000 and £125,140, and the 45 percent band. The tool runs a binary search: it guesses a gross, applies the full 2026/27 forward calculation to find the resulting net, then narrows the range until the net matches your target to the penny. The forward step uses the England, Wales, and Northern Ireland bands after the personal allowance and its taper, plus employee Class 1 National Insurance at 8 percent and 2 percent. It assumes a standard tax code with no pension or student loan, so add those separately if they apply to you.
Frequently asked questions
Why is the gross-up not linear?
Because income tax and NI are banded, the gross needed for each extra pound of net rises as you move into the 40% band, the personal-allowance taper (a 60% effective band between £100k and £125,140), and the 45% band. This tool searches for the exact gross that yields your target net.
Does this calculator include pension contributions?
No. The result assumes no pension deduction and no student loan repayment. If your employer or you contribute to a pension, your net pay will differ and you should enter a higher target net to compensate, or use a full take-home calculator that supports pension inputs.
What tax code does this tool assume?
The calculator assumes a standard 1257L tax code, which gives the full personal allowance of £12,570 for 2026/27. If you are on an emergency code, a BR code, or a K code, the actual gross needed will differ. Check your payslip or contact HMRC to confirm your tax code.
How does the personal allowance taper affect the gross-up?
For gross salaries above £100,000 the personal allowance is reduced by £1 for every £2 of income above that threshold, creating an effective 60% marginal rate until the allowance is fully withdrawn at £125,140. This means the gross salary required to reach a target net in that range is significantly higher than a simple band calculation would suggest.