HomeSelf-Employed Tax Calculator

Self-Employed Tax
Calculator 2026/27

For sole traders. See the income tax and National Insurance on your profit, what you keep, and how much to put aside each month for your tax bill.

Tax year 2026/27
Your turnover: everything your business took in, before expenses
Business costs you can claim, such as stock, travel and equipment. Leave blank if none.
Yearly pay before tax from any employed job, so your tax is worked out at the right rate

How self-employed tax works

As a sole trader you pay tax on your profit, not on everything you take in. Your profit is your income (turnover) minus your allowable business expenses. You report it on a Self Assessment tax return after the tax year ends, and HMRC works out your bill from that.

Two things are charged on your profit:

You do not have to pay Class 2 National Insurance. If your profits are £7,105 or more it is treated as paid, which protects your National Insurance record. If your profits are under £7,105, you can choose to pay voluntary Class 2 at £3.65 a week.

If you also have a job

Your salary uses up your Personal Allowance and tax bands first, because your employer taxes it through PAYE. Your profit then sits on top, so more of it may be taxed at 20% or 40%. That is why the calculator asks for any salary. It shows only the extra tax caused by your profit. Class 4 is charged on your profit alone, whatever your salary.

The £1,000 trading allowance

The trading allowance lets you take up to £1,000 of trading income tax-free. If you use it, you cannot also claim your expenses. So it usually only helps if your expenses are under £1,000.

Payments on account

Once your Self Assessment bill (income tax plus Class 4) is £1,000 or more, HMRC usually asks you to pay towards next year's bill in advance. These payments on account are each half of this year's bill, due on 31 January and 31 July. You do not need to make them if your bill was under £1,000, or if more than 80% of your tax was already taken at source, for example through PAYE on a job. In your first year this can mean a large January payment: this year's bill plus the first payment towards next year. If you enter last year's bill under More options, the calculator also shows the payments on account due during this tax year and the balancing payment left on 31 January.

Worked example (England, no other job): your turnover is £34,000 and your expenses are £4,000, so your profit is £30,000. Income tax: £30,000 minus the £12,570 allowance leaves £17,430, and 20% of that is £3,486. Class 4: 6% of £17,430 (from £12,570 to £30,000) is £1,045.80. You keep £30,000 minus £3,486 minus £1,045.80, which is £25,468.20 (£2,122.35 a month). Your tax and NI come to £4,531.80, or £377.65 a month to set aside. Payments on account for next year would be two payments of £2,265.90.

Related calculators

Running a limited company instead of working as a sole trader? Our contractor calculator covers salary and dividends. If you also pay yourself dividends, see the dividend tax calculator. For the pay from an employed job, use the take home pay calculator. To see how repayments work on each plan, try the student loan calculator. All the 2026/27 rates are on one page in UK tax rates.

How this is worked out

We take your expenses (or the £1,000 trading allowance) from your turnover to get your profit. The income tax on your profit is the tax on your salary and profit together, minus the tax on your salary alone. Class 4 National Insurance is charged on your profit only, and any student loan repayment is 9% (6% for a postgraduate loan) of your total income above your plan's threshold, minus what your salary alone would repay.

What this calculator assumes

  • Tax year 2026/27, using England, Wales and Northern Ireland rates, or Scottish rates if you choose Scotland.
  • One sole trader business, with the standard Personal Allowance of £12,570 (reduced above £100,000) and tax code 1257L on any job. If you enter the tax paid through PAYE, the income tax left to pay is the tax on your salary and profit together minus that amount.
  • Blind Person's Allowance adds £3,250 to your allowance. Marriage Allowance received cuts your tax by up to £252 if you pay no more than the basic rate (starter, basic or intermediate in Scotland); transferred, it lowers your allowance by £1,260 if your income is below £12,570.
  • No other income (such as savings interest, dividends or rent), no pension contributions and no other reliefs or losses from earlier years.
  • No Class 2 National Insurance is charged. Class 1 National Insurance on a job is left out, because your employer already takes it.
  • Payments on account for next year are half of this year's income tax and Class 4 (not student loan). If you enter last year's bill, this year's payments on account are half of it each, and the balancing payment is this year's total minus those two payments. Figures are rounded to the nearest penny.

Sources

Rates checked against GOV.UK on 12 October 2026. Read how we calculate or tell us about a mistake.

Frequently asked questions

No. If your profits are £7,105 or more, Class 2 is treated as paid, which protects your National Insurance record. If your profits are under £7,105, you can choose to pay voluntary Class 2 at £3.65 a week to keep your record up to date.

It lets you take up to £1,000 of trading income a year tax-free. If you use it, you cannot also claim your business expenses, so it usually only helps if your expenses are under £1,000.

The calculator shows a monthly figure: your income tax, Class 4 National Insurance and any student loan repayment for the year, divided by 12. Payments on account can make some January bills larger, so plan for when each payment is due.

They are advance payments towards next year's tax bill. Each is half of this year's Self Assessment bill (income tax plus Class 4), due on 31 January and 31 July. You do not need to make them if your bill was under £1,000 or more than 80% of your tax was already taken at source, for example through PAYE.

Your salary uses up your Personal Allowance and tax bands first, so your profit is taxed on top of it, often at a higher rate. Enter your salary in the calculator to see the extra tax your profit adds. Class 4 National Insurance is still worked out on your profit alone.

No. It is an estimate to help you budget. Your actual bill comes from your Self Assessment tax return. You may want to check with HMRC or an accountant if your situation is more complex.