Reverse Tax Calculator UK 2026/27
Work backwards from your take-home pay to find your gross salary — the reverse of a normal tax calculator
What is a reverse tax calculator?
A normal tax calculator starts with your gross salary and works out how much tax and National Insurance you will pay. A reverse tax calculator does the opposite: it starts with the take-home (net) pay you want to end up with, and works backwards to tell you the gross salary you need to earn to get there in 2026/27. This is useful when negotiating a salary, setting a contractor day rate, or working out what to ask for in a job offer so your take-home pay hits a specific target.
How to use this reverse tax calculator
Enter the take-home amount you want — annually or monthly — along with your student loan plan and any pension contribution, and the calculator instantly works out the exact gross salary required, plus a full breakdown of Income Tax, National Insurance and your effective tax rate.
Frequently asked questions
To take home £2,500/month (£30,000/year) in 2026/27 with no student loan or pension, you need a gross salary of approximately £38,600. The exact figure depends on your tax code, pension contributions, and student loan.
Gross salary is your total pay before any deductions. Net salary (take-home pay) is what you receive after income tax, National Insurance, pension contributions, and student loan repayments are deducted by your employer via PAYE.
Pension contributions are deducted before tax (for most workplace pensions), which reduces your taxable income. This means a higher pension contribution lowers the gross salary needed to achieve your desired take-home pay.
To take home £3,000 a month (£36,000 a year net) with a standard tax code and no other deductions, you'd typically need a gross salary of roughly £46,000–£48,000 a year, depending on your pension contributions and student loan status. Enter £3,000 as your monthly take-home target in the calculator above for your exact required gross salary.
Worked example
Someone wants to take home £2,500 per month (£30,000/year). With no student loan and no pension, what gross salary do they need?
| Desired take-home | £30,000/yr |
| Gross salary needed (calculated) | £38,623 |
| Personal Allowance | £12,570 |
| Taxable income | £26,053 |
| Income tax (20%) | £5,211 |
| National Insurance (8%) | £3,412 |
| Total deductions | £8,623 |
| Take-home pay | £30,000 ✓ |
How the calculation works
This calculator uses a binary search algorithm to find the exact gross salary that results in your desired net pay:
- Start: Set a range of possible gross salaries (£0 to £500,000)
- Midpoint test: Calculate take-home for the midpoint salary using 2026/27 HMRC rates
- Narrow range: If take-home is too low, raise the lower bound; if too high, lower the upper bound
- Repeat: After 50 iterations the result converges to within pennies of the correct gross salary
- Deductions: Income tax, NI, pension contributions, and student loan are all accounted for
All calculations run entirely in your browser. No data is sent to our servers, stored, or shared with any third party.
Results are estimates based on 2026/27 HMRC rates and are intended as a guide only. They do not constitute financial or tax advice. Always verify with HMRC or a qualified accountant for your specific circumstances.
Frequently asked questions
What is a reverse tax calculator?
A reverse tax calculator works backwards from your desired take-home (net) pay to tell you the gross salary you need to earn before Income Tax and National Insurance are deducted. It is the opposite of a standard salary calculator, which starts from gross pay.