Free tool

Self-employed tax calculator

Estimate the Income Tax and Class 4 National Insurance on your profit as a sole trader. It assumes your profit is your only income.

Your self-employed income minus your allowable expenses.

Tax year
Where you live

Answer

Enter your profit, choose the tax year and where you live, and press Work out my tax.

What this does and doesn’t include

  • It includes Income Tax and Class 4 National Insurance on your self-employed profit, with the standard Personal Allowance, reduced above £100,000.
  • It assumes your profit is your only income. A salary, a pension, savings interest, dividends or rent change what you pay, and so do reliefs such as pension contributions. None of them are included here.
  • It isn’t what you’ll be asked to pay in January. On top of the bill for the year, you usually make payments on account towards the next one. Read the guide to payments on account
  • The rates, bands and how they apply to sole traders: read the guide to tax and National Insurance

An estimate, not advice. Figures from HMRC’s Income Tax rates and allowances and National Insurance rates and allowances, checked 20 October 2026. Nothing you type here is stored.

Tuppin works out your profit from your income and expenses as you record them. See how Tuppin keeps your records