Self-employed tax calculator for UK sole traders

It uses current 2026/27 GOV.UK/HMRC rates for Income Tax (England/Wales/Northern Ireland and Scotland), Class 4 and Class 2 National Insurance, and the £1,000 trading allowance, checked directly against the primary source pages on 22 August 2026 (Class 1 employee National Insurance, used only by the optional salary comparison, checked 24 August 2026). It covers self-employment income only: it does not model combining other PAYE income with self-employment, pensions, student loans, payments on account or trading losses, and it is general information, not personalised tax advice.

Enter your turnover (or day rate) and expenses; the calculator works out your taxable profit by deducting your expenses. It does not automatically switch to the £1,000 trading allowance instead, because GOV.UK excludes some people from using it (broadly, trade or property income connected to your own company, partnership or employer). If you tick the eligibility box in Advanced options, it then uses whichever of the allowance or your expenses gives the better result; left unticked, it uses your actual expenses only.

For 2026/27, Class 2 is treated as paid automatically, with nothing to pay, once your profit reaches £7,105. Below that, paying it is voluntary, and only worth doing to protect your State Pension record. The calculator reflects this rather than treating Class 2 as a flat charge.

Yes. In UK tax terms, a sole trader is self-employed, so this calculator is designed for the same core question people mean by 'sole trader tax calculator' or 'self employment tax calculator': enter turnover or a day rate plus business expenses, then estimate taxable profit, Income Tax, National Insurance and take-home pay. It does not model limited-company salary/dividends or combine PAYE employment income with self-employment.

This calculator estimates your overall Income Tax and National Insurance position from your turnover or day rate. If you work under the Construction Industry Scheme, use TBV's CIS calculator instead: it handles the CIS-specific questions this one doesn't, working out an invoice deduction or a year-end position against CIS already deducted.

No. Every calculation runs in your browser using the figures you enter; nothing is transmitted, stored or logged.

In Advanced options, enter a gross annual salary to see its estimated annual take-home using standard Category A Class 1 employee National Insurance (0% to £12,570, 8% to £50,270, 2% above, 2026/27 annual thresholds), shown next to your self-employed take-home from the figures above. This is an annualised estimate, not a payslip: real Class 1 NI is worked out per pay period against HMRC's weekly/monthly thresholds rather than by annualising a salary, and those don't multiply out to exactly the annual figures used here, so an actual payslip can differ slightly, more so if you're on a different NI category. It models that one salary entirely on its own: no other income, pension contributions or student loan, and it isn't added to your self-employed figures. It also doesn't account for employment benefits like holiday pay, sick pay or an employer pension contribution, which a salary usually includes and self-employment doesn't.