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Calculator · 2026/27 tax year

Self-employed tax calculator

Estimate your Income Tax and Class 4 National Insurance, how much to set aside, and what you'll pay in January. Works for the whole UK, including Scotland.

Your figures for the year

Scotland has its own Income Tax bands. National Insurance is the same everywhere.
£
Everything you invoiced or were paid, before expenses.
£
If under £1,000, we'll use the £1,000 trading allowance instead.
£
Gross pay before tax. Leave at 0 if you're only self-employed.
£4,532
Estimated tax and National Insurance on your self-employed profit
13%of every payment to set aside
£378to set aside each month
£6,798due by 31 January (bill + first payment on account)
£2,266due by 31 July
Income£36,000.00
Expenses−£6,000.00
Profit£30,000.00
Income Tax on profit£3,486.00
Class 4 National Insurance£1,045.80
Total bill£4,531.80
  • Register for Self Assessment by 5 October after the tax year ends if you haven't already.
  • Payments on account apply: half of this bill again goes towards next year, due in January and July.
  • Making Tax Digital will apply from April 2027 for self-employed and property income over £30,000.

Want to track this through the year as payments come in? Our spreadsheet does these sums automatically from your invoices and expenses.

See the tracker

How this is worked out

Profit is your income minus expenses (or the £1,000 trading allowance if that's higher). Income Tax is charged on profit above your £12,570 Personal Allowance, at 20% up to £50,270, 40% up to £125,140 and 45% above. The allowance shrinks by £1 for every £2 of income over £100,000. If you have a job, your salary is counted first.

In Scotland, Income Tax on income above the Personal Allowance is charged at 19% (starter), 20% (basic), 21% (intermediate), 42% (higher) from £43,663, 45% (advanced) from £75,001 and 48% (top) above £125,140.

Class 4 National Insurance is 6% on profit between £12,570 and £50,270, and 2% above that. Payments on account apply when your bill is over £1,000, unless at least 80% of your total tax was already taken through PAYE.

An estimate for planning only. It doesn't include student loan repayments, pension contributions, Gift Aid, other income or High Income Child Benefit Charge. Read more in our guide to setting aside tax.