UK Self-Employed Tax Calculator
Estimate income tax and Class 4 National Insurance on your profit and what you keep.
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How to do it
- 1Fill in the boxes
Type your numbers or pick the options you need.
- 2See the result
The answer updates right away as you change a value.
- 3Use it
Copy the result or note it down. Nothing is sent anywhere.
About this tool
Enter your yearly profit after business expenses. The tool works out income tax with the personal allowance, Class 4 National Insurance, how much to set aside each month and your take-home profit. Rates and thresholds are for the 2026-27 tax year and can change. A guide only, check gov.uk for the official figures.
What is included
Income tax uses the 20, 40 and 45 percent bands and the personal allowance, which tapers away above £100,000. Class 4 NI is 6 percent between £12,570 and £50,270 and 2 percent above. Class 2 is no longer compulsory.
Example
On £50,000 profit the tax and NI come to about £11,400, which is roughly £950 a month to set aside.
Not included
Payments on account, student loan repayments, pension contributions and the high income child benefit charge are not modelled. Use the profit after allowable expenses, not your turnover.
Frequently asked questions
Should I enter turnover or profit?
Profit. That is turnover minus allowable business expenses.
How much should I set aside?
The monthly set-aside line is the tax and NI divided by twelve. Many people keep a little more as a safety margin.
Do I pay Class 2 NI?
Not compulsorily now. A small voluntary payment can protect your State Pension record.
When is the tax due?
A balancing payment and the first payment on account are due on 31 January after the tax year, with the second payment on account on 31 July.