Free tool
Self-employed tax calculator 2026/27
Put in your sales and expenses to see your income tax, National Insurance and take-home pay. Updated for the 2026/27 tax year.
How the calculator works it out
Your taxable profit is your sales minus your allowable expenses. If your expenses are under £1,000, the calculator uses the £1,000 trading allowance instead, because that gives a bigger deduction. Income tax is then charged on your total income above the £12,570 Personal Allowance, and the calculator shows the part caused by your self-employment.
| Band | Rate |
|---|---|
| Personal Allowance: first £12,570 | 0% |
| Basic rate: £12,571 to £50,270 | 20% income tax |
| Higher rate: £50,271 to £125,140 | 40% income tax |
| Additional rate: over £125,140 | 45% income tax |
| Class 4 NI: profits £12,570 to £50,270 | 6% |
| Class 4 NI: profits over £50,270 | 2% |
The Personal Allowance shrinks by £1 for every £2 of income over £100,000, and the calculator allows for that. Class 2 National Insurance is treated as paid once profits reach £7,105, so it does not add to your bill.
Worked example: £40,000 sales and £6,000 expenses
- Profit: £40,000 − £6,000 = £34,000.
- Taxable income: £34,000 − £12,570 = £21,430.
- Income tax: £21,430 × 20% = £4,286.
- Class 4 National Insurance: £21,430 × 6% = £1,285.80.
- Total: £5,571.80, leaving about £28,428 from the business.
Because the bill is over £1,000, HMRC would normally also ask for payments on account towards the next year. Our payments on account explainer shows how that first January can catch people out.
What the calculator leaves out
It is an estimate for one sole trade. It does not include pension contributions, Gift Aid, student loan repayments, rental or dividend income, capital allowances on bigger purchases, or Scottish income tax rates. If any of those apply, your real figure will differ, sometimes a lot.
We work out the exact figure when we prepare your Self Assessment tax return, and we tell you what you owe well before 31 January.
Common questions
How much tax do I pay as a sole trader?
You pay income tax at 20% on profit between £12,570 and £50,270, 40% above that and 45% over £125,140, plus Class 4 National Insurance at 6% between £12,570 and £50,270 and 2% above. On £30,000 of profit that is £4,531.80 in total for 2026/27.
Do I pay tax on my turnover or my profit?
On your profit: sales minus allowable expenses. Turnover still matters for VAT (the £90,000 registration threshold) and for Making Tax Digital for Income Tax, which uses turnover, not profit.
When do I pay the tax for 2026/27?
The balancing payment is due on 31 January 2028, along with your first payment on account for the following year if one applies. See our tax deadlines page for every date.
Should I put money aside each month?
Yes. A simple habit is to move a set share of every invoice into a separate savings account. Use the effective rate the calculator shows as a starting point, and remember payments on account in your first full year.
Next step
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