Self-employed tax calculator
Self-employment income minus business expenses. Profit, not turnover.
Under CIS?
The tax contractors withheld from your payments. It counts as tax already paid, so it comes off the bill. The deduction statements from your contractors carry the figure.
Income Tax
£0.00
Type your profit above and the bill works itself out.
Class 4 National Insurance
£0.00
Total for the year
£0.00
Class 2 National Insurance: with profits of £7,105 or more it counts as paid automatically, nothing to pay. Below that, nothing is due either; voluntary contributions at £3.65 a week exist to protect your State Pension record.
This assumes self-employment is your only income. Wages, rental income, savings interest or dividends change the position: see what's left out, below.
How the numbers work
Two taxes come out of a sole trader's profit. Income Tax is charged on profit above your Personal Allowance of £12,570, at the band rates for where you live. Class 4 National Insurance is charged on the profit itself: 6% on the slice between £12,570 and £50,270, then 2% on anything above. Both are worked out at Self Assessment and paid as one bill.
In England, Wales and Northern Ireland there are three rates for 2026-27: 20% basic, 40% above £50,270 of income, 45% above £125,140. In Scotland there are six, from a 19% starter rate to a 48% top rate, and they apply to your trading profit if you live there. National Insurance is not devolved, so Class 4 is the same everywhere. The full band tables are in how much tax will you pay as a sole trader.
Two details the calculator handles for you. Above £100,000 of income the Personal Allowance shrinks by £1 for every £2 over, and it's gone at £125,140. And if you're a subcontractor under CIS, the tax your contractors withheld counts as tax already paid: the calculator nets it off, which is how a CIS refund happens.
What this leaves out
The calculator works on trading profit alone, so the number is right when self-employment is your only income. It leaves out, honestly:
- Other income. Wages, rental income, savings interest and dividends all use up band space, so tax on the same profit comes out higher when they're in the picture.
- Student loan repayments. Collected through the same Self Assessment bill: 9% of income over your plan's threshold, 6% for postgraduate loans.
- The Child Benefit charge. Claws back Child Benefit once income passes £60,000, all of it by £80,000.
- Pension contributions and Gift Aid. Both can widen your basic-rate band and lower the income the taper looks at.
SoleTax's in-app estimate handles all four, from your real records, as you earn.
Quick answers
How much on £40,000 of profit?
£7,131.80 for 2026-27 in England, Wales or Northern Ireland: £5,486.00 of Income Tax and £1,645.80 of Class 4. In Scotland it's £7,196.87. That's the worked example from the full guide, and the calculator reproduces it.
Is my turnover taxed?
No. Tax is on profit: what's left after business expenses. Every expense you record brings the bill down, which is why claiming everything you're entitled to matters.
When do I pay it?
By 31 January after the tax year ends. Once the bill reaches £1,000, HMRC also collects two advance instalments towards the following year, payments on account, due 31 January and 31 July. The escape: more than 80% of the year's tax already collected at source means no instalments.
Why is Scotland different?
Income Tax rates are set by the Scottish Parliament for people who live in Scotland, and they apply to self-employed profits. National Insurance and the Personal Allowance stay UK-wide.
More free tools
What will you pay on 31 January?
Payments on account from your own bill, including the first-year 150% surprise.
What can you claim for your miles?
Your mileage claim at the 2026-27 flat rates: 55p, the 10,000-mile switch, 24p motorcycles.
Do the MTD rules apply to you?
Four quick questions, your start date at the end: April 2026, 2027, 2028, or not yet.
Know your number all year, not just today
SoleTax keeps a running estimate of the tax to set aside as you earn, from your real receipts, miles and invoices, Scotland included. 14 days free, no card needed.
Join the betaSources: gov.uk, Income Tax rates and Personal Allowances; Scottish Income Tax; self-employed National Insurance rates; understand your Self Assessment bill (payments on account). All re-read 8 July 2026.