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Sole Trader Tax Calculator

Estimate Income Tax and Class 4 National Insurance on your self-employment profit.

£40,000
Taxable profit
£7,132
Tax + NI owed
£32,868
Take-home profit
Income£45,000
Allowable expenses−£5,000
Taxable profit£40,000
Personal AllowanceShared across all income sources£12,570
Income TaxAttributable to self-employment profit−£5,486
Class 4 National Insurance6% between £12,570–£50,270, 2% above−£1,646
Tax & NI on this profit£7,132

2026/27 rates. Class 2 NI was abolished for most self-employed people from 2024/25 (voluntary Class 2 still available to protect state pension entitlement — not included here). Assumes no student loan and standard Personal Allowance. Guidance only — not tax advice; a qualified accountant will find reliefs a calculator can't.

Figures use published 2026/27 UK tax rates and are simplified estimates for guidance only — not tax, accountancy, or financial advice. Your actual liability depends on your full circumstances; confirm withGOV.UK or a qualified accountant before acting.