The net pay you want after all deductions.
Salary sacrifice pension reduces your taxable income — the gross needed will be higher.
You Want
£30,000.00
net / year
You Need
£36,778.32
gross / year
Gross Salary Needed
£36,778.32
Your Take Home
£29,999.99
Total Deductions
£6,778.33
Effective Rate
18.4%
Marginal Rate
28.0%
Annual
£36,778.32
gross
£29,999.99
net
Monthly
£3,064.86
gross
£2,500.00
net
Weekly
£707.28
gross
£576.92
net
Everything you need to know about reverse tax calculations in the UK
What is a reverse tax calculation?
A reverse tax calculation works backwards from your desired take-home (net) pay to determine the gross salary you need to earn. This is useful when negotiating a salary, planning a budget based on net income, or understanding how much you need to ask for before deductions.
Why can't I just add the tax rate to my net pay?
The UK tax system uses progressive bands — different portions of your income are taxed at different rates. Your Personal Allowance (£12,570 tax-free), basic rate band (20%), higher rate band (40%), and additional rate (45%) all interact. Plus National Insurance, student loans, and pension deductions add further complexity. Our calculator handles all of this using an iterative algorithm to find the exact gross figure.
What about the £100k–£125k trap?
If the gross salary falls between £100,000 and £125,140, you lose £1 of Personal Allowance for every £2 earned above £100,000. This creates an effective 60% marginal tax rate in that band. Our calculator accounts for this — you'll see the effective and marginal rates in your results.
How does salary sacrifice pension affect this?
Salary sacrifice pension contributions reduce your gross pay before tax and NI are calculated. This means you'll need a higher gross salary to achieve the same net pay, but you'll also be building pension savings and paying less tax overall. Use the "Pension Contribution" option above to see the impact.
HMRC-Aligned: This calculator uses official HMRC rates and thresholds for the 2025/26 tax year (6 April 2025 – 5 April 2026). Results are indicative — for complex situations, consult a qualified accountant.
This calculator uses official rates and thresholds from:
Last verified: February 2026 · Tax year 2025/26. Results are indicative — consult a qualified accountant for personalised advice.
Reviewed by M. Samiuddin Quadri, ACCA — Chartered Certified Accountant at Gladstone & Co. · Updated for the 2025/26 tax year.
Disclaimer: This calculator provides estimates based on current HMRC rates and thresholds for the 2025/26 tax year. It does not constitute professional tax, financial, or legal advice. Your actual liability may differ depending on your individual circumstances. Always consult a qualified accountant or tax adviser before making financial decisions. Read our terms