Self-Employed Tax Calculator
Use our free self-employed tax calculator to estimate your income tax and Class 4 National Insurance for the 2026/27 tax year. Enter your annual profit, which is your income after business expenses, and we will estimate your tax bill and what you should set aside each month.
Self-Employed Tax Calculator
Estimate your income tax and Class 4 National Insurance for the 2026/27 tax year.
| Profit | £0 |
| Income tax | £0 |
| Class 4 National Insurance | £0 |
| Total tax and NI | £0 |
| Set aside per month | £0 |
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Estimate only, based on 2026/27 rates for England, Wales and Northern Ireland (Personal Allowance £12,570; income tax 20%, 40%, 45%; Class 4 NI 6% then 2%). Class 2 NI is no longer required for most. It assumes no other income and is not tax advice.
How self-employed tax is worked out in 2026/27
If you are self-employed, you pay income tax and National Insurance on your profit, which is your income after allowable business expenses. The first £12,570 is covered by the Personal Allowance. Income tax is then 20 percent up to £50,270, 40 percent up to £125,140 and 45 percent above. Class 4 National Insurance is 6 percent on profits between £12,570 and £50,270, and 2 percent above. Class 2 National Insurance is no longer required for most self-employed people, though it can still be paid voluntarily to protect benefit entitlements.
Claim every expense you are entitled to
The more legitimate business expenses you claim, the lower your profit and your tax bill. If you work under CIS, you may also have had too much tax deducted at source and be due a refund. See our guides to CIS tax rebates and working from home as self-employed, and try our other tax calculators.
Check what you are owed with TaxPro on a no win, no fee basis.
Frequently asked questions
What counts as profit?
Your profit is your total self-employed income minus your allowable business expenses. You pay income tax and Class 4 National Insurance on the profit, not your turnover.
Do I still pay Class 2 National Insurance?
For most self-employed people Class 2 is no longer required. You can still pay it voluntarily to protect your State Pension and certain benefits if your profits are low.
How much should I set aside for tax?
A common rule of thumb is to set aside around a quarter to a third of your profit, but this calculator gives you a clearer monthly figure based on your actual profit.