Sole Trader Tax Calculator 2026/27
Estimate the Income Tax and Class 4 National Insurance on your sole-trader profit.
Enter your expected annual profit, not turnover. Profit means your business income after allowable business expenses. This tool estimates standard England, Wales and Northern Ireland Income Tax bands and Class 4 National Insurance for the current tax year.
What this calculation includes
The estimate applies the personal allowance (including the high-income taper), standard Income Tax bands and Class 4 National Insurance to the profit entered. It assumes you have no other taxable income and have not made pension contributions or Gift Aid donations that might change your result.
What it does not include
This calculator does not model payments on account, student-loan repayments, High Income Child Benefit Charge, Scottish income-tax bands, capital allowances, loss relief or voluntary Class 2 National Insurance. Use it to set a tax reserve, then speak to an accountant for a personalised calculation.
Your first substantial Self Assessment bill can include advance payments toward the following year. Use our Payments on Account Calculatorto see the potential cash-flow effect.
Related guides
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Information on this page is general guidance for UK small businesses and is not financial, tax or legal advice. Tax rules, allowances and product terms change. Always check current information with HMRC, Companies House or a qualified professional before making decisions.