Self-Employed Tax Calculator UK 2026/27
Enter what you earned and what you spent. You will see your tax bill, your real take-home and how much of every payment to put aside, so January never comes as a shock.
| Income | £45,000 |
|---|---|
| Business expenses | £5,000 |
| Taxable profit | £40,000 |
| Income Tax on your profit | £5,486 |
| Class 4 National Insurance | £1,646 |
| Take-home | £32,868 |
In your first year, the January bill is the year's tax (£7,132) plus the first payment on account for next year (£3,566): £10,698. Another £3,566 follows on 31 July.
- Class 2 NI is no longer charged. Your profit is above £7,105, so the year counts for your State Pension automatically.
- Making Tax Digital: with £45,000 of income you will need to send quarterly updates through compatible software from April 2027 if this is your 2025/26 income. How it works.
- Figures are for the 2026/27 tax year (6 April 2026 to 5 April 2027) and use the official HMRC rates.
How sole traders are taxed in 2026/27
You pay tax on your profit: income minus allowable expenses. Two things come off it. Income Tax uses the same bands as employees: the first £12,570 is tax-free, then 20% up to £50,270, 40% up to £125,140 and 45% above. Class 4 National Insurance is 6% on profit between £12,570 and £50,270 and 2% above that.
On £30,000 profit that is £3,486.00 Income Tax and £1,045.80 Class 4, leaving £25,468.20 to live on.
Class 2 is gone
Since April 2024 nobody has to pay Class 2 National Insurance. If your profit is £7,105 or more, the year still counts towards your State Pension automatically. Below that you can choose to pay £3.65 a week to fill the gap.
The £1,000 trading allowance
If your income from self-employment is £1,000 or less in a tax year, it is tax-free and you do not need to tell HMRC. Above that, you can deduct a flat £1,000 instead of your real expenses when that is better. The calculator picks the larger one for you. It cannot be used for income from your own company, your employer or a partnership.
Payments on account
Once your Self Assessment bill is £1,000 or more, HMRC asks for next year's tax in advance: half on 31 January and half on 31 July, unless more than 80% of your tax was already collected at source, for example through PAYE. In your first year that means paying roughly one and a half years of tax in one January. Read the payments on account guide to plan for it.
Take-home by profit
- £20,000 profit after tax
- £30,000 profit after tax
- £40,000 profit after tax
- £50,000 profit after tax
- £60,000 profit after tax
- £80,000 profit after tax
- £100,000 profit after tax
Frequently asked questions
How much should I save for tax when self-employed?
With no other income, set aside about 15% of profit at £30,000, 19% at £50,000 and 28% at £80,000. The calculator shows your exact share, including student loan, so you can move that percentage into a savings pot every time a customer pays.
When is self-employed tax due?
For the 2026/27 tax year the return and the bill are due by 31 January 2028. If you pay payments on account, the first is due 31 January 2027 and the second 31 July 2027.
I have a job and a side business. How is that taxed?
Your salary uses your Personal Allowance first through PAYE, so the profit is taxed at your next rate, often 20% or 40% from the first pound. Enter your salary and the calculator shows the extra tax due on the profit alone.
Should I become a limited company instead?
Not just for tax, if you take all the profit out. Since dividend tax rose in April 2026, a company paying everything out leaves you £20 less at £60,000 profit and £4,102 less at £100,000. It helps when you can leave profit in the company. Compare both in the limited company calculator and the sole trader vs limited company guide.
Sources: HMRC rates and allowances 2026/27, gov.uk Self-employed National Insurance rates, gov.uk Understand your Self Assessment tax bill, gov.uk Tax-free allowances on property and trading income. General information, not tax advice.