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Self-Employed Tax Calculator

Income tax and Class 4 NI for sole tradersRuns in your browser

Take-home after tax
£34,348
Per month
£2,862.35
Tax and NI to pay
£7,652
Set aside
18.2% of profit
Per year
Profit£42,000.00
Income tax£5,886.00
Class 4 National Insurance£1,765.80
Take-home£34,348.20
Income tax by band
BandRateIncome in bandTax
Basic rate20%£29,430.00£5,886.00

Class 4 NI is 6% of profits between £12,570 and £50,270 and 2% above. Class 2 NI is no longer compulsory; you get a National Insurance credit automatically once profits pass the small profits threshold. Tax is paid through Self Assessment by 31 January, and if your bill is over £1,000 you'll usually also make payments on account.

These are estimates based on 2026/27 rates and the inputs you give. Your actual position can differ (other income, benefits in kind, tax code changes, scheme rules). This is not financial or tax advice.

Also works as:sole trader tax calculatorself assessment calculatorclass 4 NI calculator

How it works

Worked example

Input: £40,000 profit in England, no pension or student loan.

  1. Income tax: 20% × (£40,000 − £12,570) = £5,486.
  2. Class 4 NI: 6% × £27,430 = £1,645.80.

Result: £7,131.80 to pay; you keep £32,868.20.

Sources

How to use

  1. 1Enter your turnover and allowable expenses.
  2. 2Add any personal pension contributions.
  3. 3Set your region and student loan.
  4. 4See the tax and NI to pay and what you keep.

FAQ

What National Insurance do self-employed people pay?

Class 4 NI: 6% on profits between £12,570 and £50,270 and 2% above. Class 2 is no longer compulsory.

How much should I set aside for tax?

Use the percentage this calculator shows; for most basic-rate sole traders it's around 15–25% of profit. Remember payments on account if your bill is over £1,000.