UK Self Assessment Tax Calculator
Estimate your self-assessment tax bill
Calculate income tax, National Insurance and take-home profit for the 2026/27 tax year.
Total income minus allowable business expenses.
Monthly profit before tax
£5,000.00
Estimated monthly net
£3,842.62
Common amounts:
Your estimated tax and take-home profit
Estimate based on self-employed profit for the tax year. Your actual tax bill may differ if you have other income or expenses.
Each payment on account
£6,944.30
Two instalments: 31 January and 31 July (each normally 50% of this year's Income Tax + Class 4 NI). Total payments on account: £13,888.60. May not apply if more than 80% of your tax is collected outside Self Assessment.
Tax Breakdown
Income
Tax and National Insurance
Key Deadlines
5 Oct
Register
31 Jan
File & Pay
31 Jul
2nd Payment
About the Self-Employed Tax Calculator
Use this UK self-employed tax calculator to estimate your Income Tax, National Insurance and take-home profit for the 2026/27 tax year.
Enter your annual business profit after allowable expenses to see an estimate of your tax bill, Class 2 NI, Class 4 NI and net income.
The calculator can also estimate payments on account: two instalments (31 January and 31 July), each normally 50% of your Income Tax and Class 4 NI bill when that bill is £1,000 or more. They may not apply if more than 80% of your tax is collected outside Self Assessment.
This tool is designed for freelancers, sole traders and self-employed individuals in England, Wales and Northern Ireland.