UK Self-Employed Tax Calculator
Estimate Income Tax, National Insurance and your take-home profit after allowable business expenses.
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UK Self-Employed Tax Calculator – Estimate Income Tax and National Insurance
Understand how much tax and National Insurance you may need to pay when working for yourself in the UK. This UK Self-Employed Tax Calculator estimates your taxable business profit, Income Tax attributable to your business income, Class 4 National Insurance and optional voluntary Class 2 contributions.
Enter your business turnover, allowable expenses, other income and Personal Allowance to estimate your tax and take-home business profit.
What Is Self-Employed Tax in the UK?
Self-employed people generally pay tax on their business profits rather than their total business turnover. Business profits are calculated after deducting eligible business expenses or, where appropriate, using the trading allowance.
Depending on your circumstances and profit level, you may need to pay:
- Income Tax: Tax on your taxable income, including self-employment profits.
- Class 4 National Insurance: Contributions calculated on qualifying self-employed profits.
- Voluntary Class 2 National Insurance: Contributions that eligible people may choose to pay to protect their National Insurance record.
How Does the UK Self-Employed Tax Calculator Work?
The calculator uses your financial details to estimate business profit and the associated tax and National Insurance.
- Enter your annual business turnover.
- Enter allowable business expenses or an optional trading allowance.
- Add any other taxable income.
- Enter your Personal Allowance and select your Income Tax region.
- The calculator estimates the additional Income Tax attributable to your business profit.
- It calculates estimated Class 4 National Insurance and any selected voluntary Class 2 contribution.
- It subtracts estimated tax and National Insurance from business profit to show estimated take-home profit.
How to Calculate Self-Employed Business Profit
Your taxable business profit is generally your business income after eligible business expenses. This calculator allows you to enter either allowable expenses or a trading allowance.
If you enter a trading allowance, the calculator uses that allowance instead of your entered business expenses. It does not deduct both amounts together.
The calculator limits the trading allowance deduction to £1,000. The trading allowance and actual expenses have different eligibility rules, so choose the appropriate method for your circumstances.
What Is the Trading Allowance?
The trading allowance is a tax allowance that may allow eligible individuals to receive up to £1,000 of trading or miscellaneous income tax-free. Depending on your circumstances, you may use the allowance instead of deducting actual allowable expenses.
This calculator provides a field for an allowance of up to £1,000. If you enter an amount greater than zero, it uses that amount instead of your business expenses.
How Is Self-Employed Income Tax Estimated?
The calculator estimates Income Tax attributable to your business profit by comparing the estimated tax on your combined income with the estimated tax on your other income alone.
This approach considers the effect of adding your business profit to other taxable income. It also applies the Personal Allowance and the tax bands programmed for the selected region.
The calculator includes separate band structures for England, Wales and Northern Ireland, and Scotland. Scottish Income Tax bands differ from the rest of the UK for non-savings, non-dividend income.
| Region selected | Income Tax calculation |
|---|---|
| England, Wales or Northern Ireland | Rest of UK tax bands |
| Scotland | Scottish Income Tax bands |
How Is Class 4 National Insurance Calculated?
Class 4 National Insurance is generally calculated on self-employed profits above the applicable lower profits limit. The calculator uses a 6% rate on profits between £12,570 and £50,270 and a 2% rate on profits above £50,270.
The calculator applies these rates to the business profit it calculates. It does not combine employment earnings and self-employed profits to determine your full National Insurance liability.
What Is Voluntary Class 2 National Insurance?
Class 2 National Insurance contributions can help eligible self-employed people protect their National Insurance record. Voluntary contributions may be relevant when profits are below the Small Profits Threshold and a qualifying National Insurance year is not otherwise secured.
The calculator includes an optional checkbox for voluntary Class 2 contributions and uses the following weekly amounts in its programmed settings:
| Tax year selected | Weekly amount used | Annual estimate (52 weeks) |
|---|---|---|
| 2025/26 | £3.50 | £182.00 |
| 2026/27 | £3.65 | £189.80 |
Example of a Self-Employed Tax Calculation
Consider a simplified example using the calculator's default business figures:
| Annual business turnover | £60,000 |
| Allowable business expenses | £10,000 |
| Estimated business profit | £50,000 |
| Other taxable income | £0 |
| Personal Allowance entered | £12,570 |
The calculator first estimates Income Tax on the £50,000 business profit, then calculates Class 4 National Insurance using its programmed thresholds. The combined estimated deductions are subtracted from the business profit to show estimated take-home profit.
The final result depends on the selected region, tax year settings and whether voluntary Class 2 contributions are included.
How to Use the UK Self-Employed Tax Calculator
- Select the tax year: Choose 2025/26 or 2026/27.
- Select your region: Choose England, Wales or Northern Ireland, or Scotland.
- Enter business turnover: Add your total annual business income.
- Enter allowable expenses: Include eligible business costs for the tax year.
- Add other taxable income: Include relevant income from employment, pensions or other sources.
- Check your Personal Allowance: Enter the allowance that applies to your circumstances.
- Consider the trading allowance: Enter an amount up to £1,000 if you are using it instead of actual expenses.
- Choose voluntary Class 2: Select the checkbox only if you want to include the calculator's voluntary contribution estimate.
- Review your results: Check estimated Income Tax, Class 4 NI, total deductions and take-home profit.