Self-Employed Tax Calculator

Estimate your Self Assessment bill as a sole trader or freelancer, and how much to put aside each month so January is not a shock.

Updated for the 2026/27 tax yearLast reviewed 7 November 2026

Your business

Everything you invoiced this tax year
£
£

Use whichever is higher. Allowable expenses include materials, travel, phone, insurance and accountancy fees.

e.g. a salary from a job, before tax
£
Self Assessment estimate2026/27
Your tax bill on your profits
£6,871.80
Income£45,000
Expenses£6,000
Taxable profit£39,000
Income Tax£5,286.00
Class 4 National Insurance£1,585.80
You keep£32,128.20
£573set aside each month
17.6%of profit goes in tax

Payments on account: because your bill is over £1,000, HMRC will usually ask you to pay half of next year’s bill in advance, by 31 January and 31 July, on top of this bill.

2026/27 rates for the self-employed

ProfitIncome TaxClass 4 NI
Up to £12,5700%0%
£12,571 to £50,27020%6%
£50,271 to £125,14040%2%
Over £125,14045%2%

Worked example: £35,000 profit

Income Tax is 20% of (£35,000 − £12,570) = £4,486. Class 4 NI is 6% of the same £22,430 = £1,345.80. Your total bill is £5,831.80, so you keep £29,168.20, and should put aside about £486 a month.

Payments on account

If your bill is more than £1,000, HMRC usually asks you to pay towards next year’s bill in two instalments of 50%, on 31 January and 31 July. In your first year this can mean paying 150% of a year’s bill in one January, so plan ahead.

Also employed? Check your job’s pay with the take-home pay calculator.

Estimate for guidance. It does not include capital allowances, losses, Gift Aid or pension contributions. Check your figures with HMRC or an accountant.

Guide: payments on account explained, with examples

Guide: sole trader vs limited company

Sources

Figures are checked against these official sources. Last reviewed 7 November 2026.

Common questions

How much tax do I pay when self-employed?

You pay Income Tax on your profit above the £12,570 personal allowance (20% up to £50,270, 40% above), plus Class 4 National Insurance at 6% on profits between £12,570 and £50,270 and 2% above that.

Do I still pay Class 2 National Insurance?

No. Since April 2024 Class 2 has not been compulsory. If your profits are above the small profits threshold (£7,105 in 2026/27) you get National Insurance credits automatically. Below that, you can choose to pay voluntary Class 2 at £3.65 a week to protect your State Pension.

What is the £1,000 trading allowance?

If your business income is small, you can deduct a flat £1,000 instead of your actual expenses. If your turnover is under £1,000 you do not need to tell HMRC at all. Use actual expenses if they are higher. The Autumn Budget 2026 raises the allowance to £3,000 from 6 April 2027.

When do I pay my Self Assessment bill?

The deadline for online returns and payment is 31 January after the tax year ends. For 2026/27 that is 31 January 2028. If your bill is over £1,000 you will usually also make payments on account in January and July.

How much should I save for tax?

A simple rule is to put aside 25 to 30% of your profit if you are a basic-rate taxpayer. This calculator shows the exact monthly figure for your profit.