UK Self-Employed Tax Calculator 2026/27

2026/27

Enter annual sole-trader profit and other non-savings income to estimate the Income Tax attributable to that profit, Class 4 National Insurance and profit after those deductions.

Rates reviewed 14 August 2026. Methodology

Published and source-checked by Mehmood Rajoka, founder and publisher. Review our editorial policy.

Scope: Standard working-age sole-trader estimate for Income Tax and Class 4 NI. It is not a complete Self Assessment bill and excludes payments on account, tax already paid, employed/self-employed NI annual-maximum adjustments, State Pension age rules and specialist Class 4 cases.

Example result

Estimated tax and Class 4 NI

£7,131.80

Profit after these deductions

£32,868.20

This is tax attributable to the entered trading profit, not your final Self Assessment bill.

Income Tax on Profit

£5,486.00

Class 4 NI

£1,645.80

Effective Rate

17.83%

of trading profit

Tax and National Insurance BreakdownView details

Income Tax attributable to profit: Band-based£40,000.00Tax £5,486.00
Class 4 — main band: 6%£27,430.00Tax £1,645.80
Class 4 — above upper limit: 2%£0.00Tax £0.00
Total estimated tax and NI: £40,000.00Tax £7,131.80

Tax and National Insurance Breakdown

Item	Rate	Amount	Deduction
Income Tax attributable to profit	Band-based	£40,000.00	£5,486.00
Class 4 — main band	6%	£27,430.00	£1,645.80
Class 4 — above upper limit	2%	£0.00	£0.00
Total estimated tax and NI		£40,000.00	£7,131.80

Class 2 threshold status

At £40,000.00 profit, Class 2 is treated as paid for your NI record if you are registered as self-employed. No Class 2 charge is included.

Official sources

Rates and thresholds are checked against the following primary sources. Review dates are shown on the relevant guide or methodology page.

Last reviewed: 14 August 2026

Scope and limitations

Read our calculation methodology

Disclaimer: This calculator provides estimates only and does not constitute tax, financial, or legal advice. Always consult a qualified professional for your specific circumstances. View methodology