Self-Employed Tax Calculator
Enter your expected self-employed profit to estimate your Income Tax and Class 4 National Insurance for the 2026/27 tax year.
Your results
| Deduction | Annual | Monthly |
|---|---|---|
| Annual profit | £35,000.00 | £2,916.67 |
| Personal Allowance | £12,570.00 | £1,047.50 |
| Income Tax | −£4,486.00 | −£373.83 |
| Class 4 National Insurance | −£1,345.80 | −£112.15 |
| Student Loan | £0.00 | £0.00 |
| Take-home profit | £29,168.20 | £2,430.68 |
Estimates only — does not include Class 2 NI, allowable expenses already deducted, or Self Assessment payment-on-account timing. Not financial advice.
How self-employed tax is calculated
As a sole trader, you pay Income Tax on your profit above your Personal Allowance, using the same bands as employees. You also pay Class 4 National Insurance on profits above £12,570, at 6% up to £50,270 and 2% above that. Both are usually paid through Self Assessment.
Frequently asked questions
What counts as "profit" for self-employed tax?
Profit is your self-employment income minus allowable business expenses. Income Tax and Class 4 National Insurance are both calculated on this profit figure, not your total turnover.
Do self-employed people pay Class 2 National Insurance?
Class 2 National Insurance is no longer compulsory since the 2024/25 tax year for most self-employed people with profits above the small profits threshold. Voluntary Class 2 payments can still be made to protect state pension entitlement, but this calculator focuses on the compulsory Class 4 contributions.
When is self-employed tax due?
Self Assessment tax for a tax year is normally due by 31 January following the end of that tax year, often alongside a payment on account for the next year, with a second payment on account due by 31 July.