Self-Employed Tax Calculator 2026/27
Estimate income tax and Class 4 National Insurance on your self-employed profit for 2026/27, and how much to set aside for your tax bill.
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How the calculation works
Income tax is charged on profit above your personal allowance at the bands for your part of the UK. Class 4 National Insurance is calculated separately on profits above £12,570. The allowance is reduced for profits above £100,000.
Things this calculator does not include
- Other income such as employment, dividends or rental profit.
- Student loan repayments.
- Pension contributions and Gift Aid.
- Payments on account and the Self Assessment deadlines.
Check your position on GOV.UK or with an accountant.
Frequently asked questions
What National Insurance do self-employed people pay?
Class 4 NI is 6% on profits between £12,570 and £50,270, and 2% above that. Class 2 is no longer compulsory, though you can pay voluntarily to protect your State Pension record.
How much should I set aside for tax?
The headline figure shows the share of your profit going to income tax and Class 4 NI. Many self-employed people move that share into a separate account each month.
What are payments on account?
If your Self Assessment bill is over £1,000 you may have to pay half of next year's estimated bill in January and half in July, on top of the balancing payment. This calculator does not model them.
What about the trading allowance?
You can deduct £1,000 from trading income instead of actual expenses. Enter your profit after whichever method gives the lower profit.
These results are estimates for general information only and are not financial or tax advice. See our disclaimer.