Self-Employed Tax Calculator (Sole Traders)
Work out Income Tax and Class 2/4 National Insurance owed on your self-employed profits as a sole trader.
2026/27 rates · last verified 15 August 2026
Your profit is above the Small Profits Threshold, so you get a qualifying year for the State Pension automatically — no Class 2 payment is due.
Income Tax breakdown
| Band | Taxed at | Amount in band | Tax |
|---|---|---|---|
| Basic rate | 20% | £22,430.00 | £4,486.00 |
Class 4 National Insurance breakdown
| Band | Taxed at | Amount in band | Tax |
|---|---|---|---|
| Main rate | 6% | £22,430.00 | £1,345.80 |
How this is calculated
As a sole trader you pay Income Tax and Class 4 (and where applicable Class 2) National Insurance on your profits. This calculator combines both to show your total tax bill.
Class 4 National Insurance is charged at 6% on profits between £12,570 and £50,270, then 2% above that — on top of Income Tax on the same profit figure. Class 2 National Insurance, which used to be a flat weekly charge for most sole traders, was abolished as a compulsory contribution from April 2024: if your profits are £7,105 or more you get a qualifying year towards your State Pension automatically, with nothing to pay.
If your profits are below £7,105, you won't get a qualifying year automatically, but you can choose to pay Class 2 voluntarily — currently £3.65 a week — to protect your State Pension record. This calculator lets you toggle that on to see the cost.
Read more: Self-employed tax explained: Income Tax and National Insurance for sole traders →
Frequently asked questions
What counts as profit for self-employed tax?
Profit is your total business income minus allowable business expenses — it's this figure, not your turnover, that's taxed.
When is self-employed tax due?
Self Assessment tax is typically due by 31 January following the end of the tax year, with a possible payment on account due the following 31 July too.
Do I need to pay Class 2 National Insurance?
Only if you want to — it's voluntary now unless your profits are below £7,105 and you want a qualifying year for the State Pension. Above that threshold, you get the qualifying year for free through Class 4.
Is there a tax-free allowance for small side-income?
Yes — the £1,000 trading allowance lets you earn up to £1,000 a year from self-employment or casual income tax-free, with nothing to report to HMRC if that's all you earn. It's applied before expenses, so you can't also deduct expenses on top of it.
What are payments on account?
If your Self Assessment bill is £1,000 or more and you haven't already paid most of it another way, HMRC asks you to pay half of next year's estimated bill in advance — one instalment on 31 January alongside that year's balancing payment, and the other on 31 July.
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