Tax calculator

Sole-trader Tax Calculator

Estimate sole-trader Income Tax and Class 4 National Insurance for 2026/27.

  • Tax year shown with the calculator
  • Assumptions explained
  • Source-linked methodology

2026/27 tax year

Estimate sole-trader Income Tax and National Insurance

Estimate Income Tax on combined non-savings income and Class 4 National Insurance on taxable self-employment profit.

Where do you live for Income Tax purposes?

Profit after allowable business expenses, not turnover.

Employment, pension or taxable property income before Income Tax. Enter £0 if none.

Do you need to include excluded or adjusted items?

Choose yes or not sure for dividends, savings, gains, student loans, tax already deducted, payments on account, losses, pension or Gift Aid adjustments, foreign income, other reliefs, or special National Insurance rules for landlords, examiners, ministers of religion or investment activity.

Your figures are used only for this calculation. They are not added to a lead record or analytics event.

What this estimator includes and excludes

It combines non-savings income for Income Tax and calculates Class 4 NI only on taxable self-employment profit. It explains Class 2 status but does not add a Class 2 charge.

It does not calculate tax already deducted, payments on account, balancing payments, refunds, dividends, savings, gains, student loans, losses, reliefs, penalties, filing obligations or special self-employed National Insurance categories.

How to understand your result

Your result is an estimate for the tax year shown on the calculator. The breakdown lists each step, the rates and thresholds used, and the date the figures were last checked against GOV.UK. Amounts are rounded the way HMRC rounds them where a rule exists.

Each calculator lists what it leaves out, such as other income, reliefs or special cases, so read the assumptions before you rely on the figure. For your own position, check your HMRC online account or speak to a qualified professional.