Self-Employment Tax Calculator

What Is a Self-Employment Tax Calculator?

A Self-Employment Tax Calculator helps sole traders, freelancers and other self-employed workers estimate how much of their business profit may be payable in UK Income Tax and Class 4 National Insurance. Unlike a salary tax calculator, the calculation starts with self-employed profit rather than gross employment wages.

This free UK Self-Employment Tax Calculator is designed for the 2026/27 tax year. Enter your annual profit after allowable business expenses, choose England, Wales, Northern Ireland or Scotland, and the calculator estimates your Personal Allowance, Income Tax, Class 4 National Insurance, total tax and remaining profit.

Why Use the Self-Employment Tax Calculator?

Self-employed tax can be difficult to estimate because Income Tax and National Insurance are calculated using different thresholds. This calculator separates the two calculations and provides a combined estimate so you can understand the potential tax impact of your profits.

How to Use the Self-Employment Tax Calculator

For the most useful estimate, enter your annual self-employed profit after allowable business expenses rather than your total business turnover.

1. Calculate your annual profit — Work out your self-employed income after deducting your allowable business expenses.
2. Enter your profit — Enter the resulting annual profit into the calculator.
3. Select your tax region — Choose England, Wales, Northern Ireland or Scotland.
4. Review the estimate — The calculator displays Income Tax, Class 4 National Insurance, total tax and estimated remaining profit.

UK Self-Employed Tax Rates for 2026/27

For the 2026/27 tax year, the standard UK Personal Allowance is £12,570. The Personal Allowance is normally the amount of income that can be received before Income Tax becomes payable. It is reduced by £1 for every £2 of adjusted net income above £100,000 and can be reduced to zero at £125,140.

Self-employed people with profits above £12,570 generally pay Class 4 National Insurance. For 2026/27, Class 4 National Insurance is charged at 6% on profits above £12,570 up to £50,270, followed by 2% on profits above £50,270.

Income Tax for Sole Traders and Freelancers

Income Tax is calculated separately from Class 4 National Insurance. In England, Wales and Northern Ireland, the main 2026/27 Income Tax rates are 20% for basic-rate taxable income, 40% for higher-rate taxable income and 45% for additional-rate taxable income.

Scottish Self-Employment Tax

Scottish taxpayers use different Income Tax bands for most non-savings income. For 2026/27, the Scottish rates are 19% at the starter rate, 20% at the basic rate, 21% at the intermediate rate, 42% at the higher rate, 45% at the advanced rate and 48% at the top rate. Class 4 National Insurance is not changed by the Scottish Income Tax system.

Self-Employment Tax Calculator Limitations

The calculator is designed as a general planning tool and assumes that the profit entered is your relevant taxable self-employed profit and that you have no other income or adjustments affecting your Personal Allowance or tax bands. If you have employment income, pension income, dividends, savings interest, property income or other taxable income, your actual liability may be different.

The estimate includes Income Tax and Class 4 National Insurance only. It does not include voluntary Class 2 National Insurance, student loan repayments, pension contributions or relief, Marriage Allowance, Blind Person's Allowance, other tax reliefs, benefits in kind, payments on account or other Self Assessment adjustments. Exact figures should be checked against your individual Self Assessment circumstances.

Frequently Asked Questions