Self-Employed and Business Tax Calculators
Last updated: October 2026 · Updated for the 2026/27 tax year
Working for yourself means you handle your own tax: Income Tax and Class 4 National Insurance through Self Assessment, possibly VAT, and for company directors Corporation Tax, salary and dividends. These calculators help you estimate what to set aside, choose a structure and avoid penalties.
Sole traders, freelancers and side hustles
Limited companies and directors
VAT and business finances
The numbers that matter in 2026/27
| Item | Figure |
|---|---|
| Class 4 National Insurance | 6% on profits between £12,570 and £50,270; 2% above. Class 2 is no longer compulsory. |
| Trading allowance | £1,000 of gross trading income can be tax-free instead of claiming expenses |
| Self Assessment dates | 31 October (paper return), 31 January (online return and payment), 31 July (second payment on account) |
| Corporation Tax | 19% on profits up to £50,000, 25% above £250,000, with marginal relief in between |
| Dividend allowance | £500 of dividend income is tax-free |
| Making Tax Digital | Quarterly updates from April 2026 above £50,000 of income, April 2027 above £30,000, April 2028 above £20,000 |
Which calculator to start with
If you are new to self-employment, start with the sole trader tax calculator to see your likely bill, then the set-aside calculator to turn it into a monthly savings target. Remember that your first Self Assessment bill can include a payment on account towards the following year, which is why many new sole traders are surprised in January. If you are deciding whether to incorporate, compare the sole trader and limited company calculators before taking advice, because the answer depends on how much profit you take out and whether you need the money personally. Contractors should check IR35 status first, as it changes the whole calculation.