Self-employed tax calculator
Enter your business income and expenses to see your income tax and National Insurance for 2026/27, and how much to set aside each month. This is for sole traders.
Your tax bill
How self-employed tax works
If you are a sole trader, you pay tax on your profit, which is your income minus your allowable expenses. You work out and pay the tax yourself through a Self Assessment tax return, instead of your employer taking it from your pay.
Income tax
Your profit is taxed in the same bands as employed pay. The first £12,570 is the tax-free Personal Allowance. After that you pay 20% up to £50,270, then 40% above it, and 45% over £125,140. Scotland has its own bands. See GOV.UK: Income tax rates.
National Insurance
Self-employed people pay Class 4 National Insurance: 6% on profit between £12,570 and £50,270, and 2% on profit above that. You do not pay Class 2 if your profit is £7,105 or more, because it is treated as paid to protect your State Pension record. See GOV.UK: Self-employed National Insurance rates.
Setting money aside
No tax is taken before you get paid, so it is easy to spend money that belongs to HMRC. The calculator shows a monthly figure to set aside. Many people keep it in a separate savings account. Your bill is normally due by 31 January, and if it is over £1,000 you may also have to make payments on account, which are advance payments towards next year's bill. See GOV.UK: Payments on account.
Expenses and the trading allowance
You can deduct costs that are wholly and exclusively for the business. Alternatively, if your income is £1,000 or less, or you prefer, you can use the £1,000 trading allowance instead of claiming expenses. You cannot do both. See GOV.UK: Trading allowance.
What this calculator assumes
- You are a sole trader and your only income is from self-employment. Employment, rental and savings income would change the tax.
- Tax year 2026/27, 6 April 2026 to 5 April 2027.
- Income tax and Class 4 National Insurance only. It does not include VAT or Class 2 voluntary contributions.
- The student loan repayment uses your profit, with no postgraduate loan.
- Pension contributions, the High Income Child Benefit Charge and payments on account are not included.
Questions people ask
How much tax do I pay on £40,000 self-employed profit?
About £7,132 in 2026/27 in England, Wales and Northern Ireland: £5,486 income tax plus £1,646 Class 4 National Insurance, leaving about £32,868.
Do I pay National Insurance if I am self-employed?
Yes, Class 4 on profit over £12,570. Class 2 is no longer payable above £7,105 profit, though it is treated as paid to protect your State Pension.
When do I have to pay my self-employed tax?
Usually by 31 January after the tax year ends, with payments on account possible on 31 January and 31 July. Register for Self Assessment with HMRC if you have not already.
Should I set up a limited company instead?
It depends on your profits and plans. A company changes how you pay yourself and what tax you pay, so ask an accountant. This calculator is for sole traders.
Is what I type stored or shared?
No. The calculation runs in your browser and nothing you enter is sent to us. Our privacy page has the details.
Is this tax advice?
No. It gives an estimate for information only. For advice on your own affairs, speak to an accountant or check GOV.UK.