Self-Employed Profit Estimator
Estimate profit from self-employment: revenue minus allowable expenses, with an illustrative UK tax estimate.
Your self-employment figures
Weekly and monthly figures are annualised (× 52 or × 12).
Total sales or fees before any costs.
Business costs HMRC allows you to deduct.
Income tax (England, Wales & NI bands) and Class 4 National Insurance on your profit — assumes this is your only income.
Enter your revenue to see an instant estimate.
Estimate only — tax rules can change.
Rates for 2026/27 (6 Apr 2026 – 5 Apr 2027) last verified against GOV.UK on 2026-08-16.
How it works
Enter your revenue and allowable expenses for a week, month or year and the calculator annualises them and shows your estimated profit. With the tax option ticked it also applies the 2026/27 (6 Apr 2026 – 5 Apr 2027) rates (or 2025/26 if selected) to show an illustrative post-tax figure.
The illustrative tax estimate
- Income tax — your profit less the £12,570 personal allowance is taxed at the England, Wales & Northern Ireland rates (20%, 40%, 45%). The allowance tapers away above £100,000.
- Class 4 National Insurance — 6% on profits between £12,570 and £50,270, then 2% above.
- Class 2 National Insurance — no longer compulsory. Profits at or above £7,105 earn an automatic NI credit; below that, voluntary contributions of £3.65 a week are available to protect benefit entitlement.
What it deliberately leaves out
The estimate assumes self-employment is your only income. It does not model employment income alongside self-employment, the £1,000 trading allowance (an alternative to claiming actual expenses), pension contributions, Scottish income tax rates on self-employment profits, VAT, payments on account or student loan repayments through Self Assessment. Your real Self Assessment calculation may differ substantially.
Frequently asked questions
How is self-employed profit calculated?
Profit is simply your revenue (everything you invoice or sell) minus your allowable business expenses. If you enter weekly or monthly figures the calculator multiplies them by 52 or 12 to get an annual picture. You pay income tax and National Insurance on profit, not on revenue.
What counts as an allowable expense?
Costs incurred wholly and exclusively for the business — for example stock, materials, business travel, a proportion of home-working costs, accountancy fees, insurance and business phone use. HMRC publishes the full rules; personal spending and most capital purchases follow different rules and are not allowable as day-to-day expenses.
What is the £1,000 trading allowance?
Instead of deducting actual expenses you can deduct a flat £1,000 trading allowance from your self-employment income. It is worthwhile when your real expenses are under £1,000 — common for small side hustles. You cannot claim both the allowance and actual expenses; this calculator models actual expenses only.
How much National Insurance do the self-employed pay?
For 2026/27, Class 4 NI is 6% on profits between £12,570 and £50,270 and 2% above that. Compulsory Class 2 was abolished in April 2024: with profits of £7,105 or more you receive a National Insurance credit automatically at no cost, and below that you can pay £3.65 a week voluntarily to protect your State Pension record.
Is this what I will actually owe HMRC?
No — it is an illustration that assumes self-employment is your only income and you take the standard personal allowance. Employment income, payments on account, pension contributions, the trading allowance, Scottish residence and other reliefs all change the real bill. Use it for planning, then complete a Self Assessment return for the actual figure.
Do I need to save for tax as I earn?
It is sensible to. Self Assessment tax is paid in arrears (31 January after the tax year, plus payments on account for many people), so setting aside a slice of each payment — often 20–30% of profit for basic-rate traders — avoids a shock bill. This calculator's tax estimate gives you a reasonable percentage to aim for.