CHERRY MONEY · FREE BUSINESS TOOLS
Know your profit.
Plan your tax.
Self-Employed Tax Calculator
Estimate Income Tax, National Insurance and a monthly tax reserve from your sole trader income and expenses.
Your annual figures
Use a full tax year’s figures. The example below starts at £50,000 income and £10,000 expenses; replace these with your own.
YOUR ESTIMATE
Plan what to set aside
Enter your figures and run the calculator to see your result.
- Business profit / loss before tax
- Taxable trading profit
- Additional Income Tax from trading
- Class 4 NI estimate
- Annual business tax reserve
- Average monthly business tax reserve
Your business tax reserve is the extra Income Tax from adding trading profit to your other income, plus Class 4. Monthly figures are annual amounts divided by 12. They do not include next-year advance payments.
Your expenses exceed trading income. This estimate shows your business loss but does not claim loss relief against other income or other years.
Other income affects your tax bands and allowance. This is business take-home only; it does not calculate take-home from employment or other income. Combined Class 1/Class 4 NI limits are excluded, so Class 4 and payment estimates may be too high if you also have a job.
Your overall tax estimate
- Personal Allowance
- Income Tax on all entered income
- Total Income Tax + Class 4
- Self Assessment before payments on account
Self Assessment payment planner
- Balancing payment for selected tax year
- First payment on account for next year
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Potential overpayment: . This is shown separately and is not offset against the payment estimates. Check how HMRC allocates it.
No claim to reduce next-year payments is assumed. Your HMRC statement may differ, especially if your income changes or you have charges excluded below.
How this tool works
Income Tax and business profit
Uses the selected year’s UK or Scottish non-savings rates and the standard Personal Allowance, including its reduction above £100,000. Other income uses the tax bands first. Trading tax is the difference between Income Tax with and without your taxable trading profit.
National Insurance
Where selected, Class 4 uses 6% on trading profit above £12,570 up to £50,270 and 2% above that. No compulsory Class 2 charge is added. Voluntary contributions and combined Class 1/Class 4 limits are excluded.
Payments on account
Includes a balancing payment after tax deducted at source and payments already made. If the remaining annual liability is at least £1,000 and at least 20% of the total, it estimates two next-year advances. This can make your first January payment larger than one year’s tax.
Scope and rounding
For UK-resident sole traders with non-savings income. Excludes savings, dividends, student loans, pension and Gift Aid relief, loss relief, capital allowances, Marriage Allowance, Child Benefit charges, capital gains, foreign tax and basis-period adjustments. Expenses are assumed deductible. Uses annual pence estimates, so tax-return whole-pound rules can differ. It does not file a return or contact HMRC.
- HMRC Income Tax rates and allowances
- Scottish Income Tax factsheet
- Self-employed National Insurance
- Self Assessment payments on account
- Trading allowance rules
Rules checked 22 October 2026. This is a planning estimate. Review your circumstances and the official guidance before acting.