Rates & sources
UK tax rates and thresholds, as published by HMRC. Scotland and Wales have devolved rates for income tax and property transactions.
Source: HMRC — Tax rates — figures refreshed at the start of each tax year.
When to use this calculator
- Before accepting a pay change, bonus, pension contribution, or salary-sacrifice option.
- When you want to compare employed, self-employed, or dividend-based income scenarios.
- When you need a simple take-home estimate before running payroll or filing returns.
- When you are approaching the £100,000 income level and want to understand the personal allowance taper effect.
- When you are planning a salary sacrifice arrangement and need to see the net pay impact before agreeing terms.
A realistic New Zealand planning example
Use these sample inputs as a quick scenario test, then change one variable at a time to compare outcomes.
Annual Gross Income (NZ$)
NZ$70,000
Business Expenses (NZ$)
5000
Pension Contributions (NZ$)
NZ$250 per month
After entering these figures, review net profit, income tax and class 4 ni together rather than in isolation — each metric tells a different part of the story. Then rerun the tool with one input adjusted to see which variable has the biggest effect on all three outputs before you settle on a plan.
How to read your results
Net Profit
Use this metric to compare scenarios side by side and understand how changes in the key inputs drive the final outcome. If the figure surprises you, isolate one variable at a time and rerun the calculation to identify which assumption is responsible.
Income Tax
Review this figure alongside your gross income so you can understand the true cost of deductions and plan around any thresholds before the tax year closes. If the figure looks higher than expected, check whether any pension or gift-aid contributions could reduce your taxable income.
Class 4 NI
Use this metric to compare scenarios side by side and understand how changes in the key inputs drive the final outcome. If the figure surprises you, isolate one variable at a time and rerun the calculation to identify which assumption is responsible.
Total Tax
Review this figure alongside your gross income so you can understand the true cost of deductions and plan around any thresholds before the tax year closes. If the figure looks higher than expected, check whether any pension or gift-aid contributions could reduce your taxable income.
Effective Rate
The effective rate lets you compare options on a true like-for-like basis rather than being misled by different compounding periods or fee structures. Use it to cut through headline marketing rates when shortlisting providers or products.
Method & assumptionsAuthoritative sources
This calculator estimates the Income Tax and National Insurance contributions owed by a self-employed individual based in the UK. It applies the current Personal Allowance, the basic and higher rate Income Tax bands applicable in England and Wales, and both Class 2 and Class 4 National Insurance thresholds as set by HMRC. The figure you should enter is your taxable profit — that is, your total trading income minus all allowable business expenses — not your gross turnover.
The calculator does not account for the High Income Child Benefit Charge, pension contributions that reduce your adjusted net income, student loan repayments, or any tax already paid through a PAYE employment. Scottish taxpayers face different Income Tax rates and bands, so results may not fully reflect their position. Always verify your liability with a qualified accountant or by using HMRC's own Self Assessment tools.
Common mistakes
- !Entering gross income when you really want take-home pay, or vice versa.
- !Ignoring pension contributions, deductions, or local tax rules that change the result.
- !Comparing monthly and annual figures without standardising them first.
- !Overlooking the National Insurance threshold changes that apply mid-year when rates or bands are adjusted in a Budget.
- !Assuming a salary sacrifice benefit reduces take-home pay by the full gross amount, rather than only the after-tax cost.
What to do next
- Check the same scenario with related pay or deduction calculators to see the full picture.
- Keep a copy of the assumptions you used so you can compare next tax year or pay period accurately.
- Read the related guides below if you are choosing between multiple income or deduction options.
- If you are self-employed, run the self-employment tax calculator alongside this result to compare the net position against employed income.
- Check whether increasing your pension contribution by even one or two percent changes the take-home significantly — use the pension calculator next.
Frequently asked
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End-of-article next steps
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