Sole Trader Tax Calculator 2026/2027

45p/mile (first 10,000) · 25p/mile after — added to expenses. HMRC rates ↗
  • Trading profit = turnover − expenses, with the £1,000 Trading Allowance applied automatically when it gives a smaller taxable profit.
  • Class 4 NI: 6% on profit between £12,570 and £50,270, 2% above (post-April 2024).
  • Class 2 NI: voluntary since April 2024 (used to be mandatory). Worth paying if your profit is under the Small Profits Threshold and you want a State Pension credit for the year.
  • Optional PAYE income stacks with self-employment income for income tax band placement, but Class 1 NI on PAYE and Class 4 NI on self-employment are computed separately.
Sole Trader / Self-Employed

Models self-employment income via Self Assessment. Optional PAYE-side input handles the common UK case of a side-hustler combining freelance with a part-time PAYE job.

Clear

How this sole trader calculator works

Enter your self-employment turnover and allowable expenses — the calculator deducts them to arrive at your trading profit, applying the £1,000 Trading Allowance automatically when it gives a lower taxable figure. Add any business miles driven and the HMRC-approved mileage allowance (45p for the first 10,000 miles, 25p after) is added to your expenses and reduces your taxable profit.

Income tax is calculated via Self Assessment band-stacking. If you also have PAYE income from an employer, enter it in the optional field and the calculator combines both sources correctly — placing self-employment profit on top of salary for tax band purposes, while keeping Class 1 NI (on PAYE) and Class 4 NI (on trading profit) separate.

Class 2 NI has been voluntary since April 2024. Tick the box if you want to pay approximately £180/year to earn a State Pension qualifying year — worth considering if your profit falls below the Small Profits Threshold.