Self-Employed Tax Calculator
UK income tax, Class 4 National Insurance, personal-allowance taper and optional student-loan repayments. Built for sole traders.
Not sure what to charge yet? Try the Freelance Day Rate Calculator first — turn a target salary into a defensible day rate, then come back here to model the tax.
Part of the UK Freelancer Tax Hub — the full cluster index.
Are you affected by MTD for Income Tax? The Self Assessment tax return is being replaced by quarterly digital updates for sole traders + landlords over threshold. Check with our MTD for Income Tax Checker — enter your income + tax year, get an instant answer.
How much UK Self Assessment tax will I pay this year?
Your 2026/27 UK Self Assessment tax bill is income tax at 20% / 40% / 45% on profit above your £12,570 personal allowance, plus Class 4 NI at 6% (£12,570-£50,270) and 2% above. Enter your profit into the calculator below for a precise figure.
Key takeaways
- Personal allowance for 2026/27 is £12,570 (unchanged from 2025/26)
- Basic rate 20% applies to profit £12,571 - £50,270
- Higher rate 40% applies to profit £50,271 - £125,140
- Class 4 NI is 6% on profits £12,570 - £50,270, then 2% above
- Payments on account become due if your bill exceeds £1,000
Editorial: Calculator maintained by FreelanceToolkit UK using HMRC's published 2026/27 rates. Worked examples cross-check against HMRC's Self Assessment worksheets. Drafted with AI assistance and checked against official sources before publishing. Editorial policy · Sources & methodology · How we test tools.
In this guide
This calculator estimates UK Self Assessment tax and Class 4 National Insurance for sole traders and freelancers at 2026/27 rates. It handles the personal allowance (£12,570), the £100k taper, basic-rate (20%), higher-rate (40%) and additional-rate (45%) bands, and Class 4 NI on profits above £12,570. It also covers Scottish bands, student-loan repayments and optional voluntary Class 2 (profits above the Small Profits Threshold, £7,105 in 2026/27, get the qualifying year automatically). It doesn't handle dividends, savings or other non-trading income — for those, use HMRC's full Self Assessment service.
Worked example
Worked example — Freelance profit £45,000, no other income
Your £45,000 profit sits entirely in the basic-rate band after deducting the £12,570 personal allowance. Income tax: (£45,000 - £12,570) × 20% = £6,486. Class 4 NI: (£45,000 - £12,570) × 6% = £1,946. Total tax + NI: £8,432. Take-home: £36,568. If HMRC required payments on account (they will next January if the total bill exceeds £1,000), you'd owe the £8,432 by 31 January 2027 plus a first payment on account of £4,216, then a second payment on account of £4,216 on 31 July 2027. Setting aside 25-28% per invoice makes January manageable.
At-a-glance comparison
| Profit level | Income tax | Class 4 NI | Total tax + NI | Take-home |
|---|---|---|---|---|
| £20,000 | £1,486 | £446 | £1,932 | £18,068 |
| £35,000 | £4,486 | £1,346 | £5,832 | £29,168 |
| £50,000 | £7,486 | £2,246 | £9,732 | £40,268 |
| £75,000 | £17,432 | £2,757 | £20,189 | £54,811 |
| £100,000 | £27,432 | £3,257 | £30,689 | £69,311 |
| £125,140+ | Personal allowance = £0 | Additional rate 45% kicks in | — | — |
Decision tree
Answer these questions in order — the first 'yes' with a clear steer usually gives you the answer.
- Have you registered for Self Assessment?
No → register by 5 October following the tax year you started. - Do you have a UTR?
No → you'll get one after registration; needed to file. - What's your tax year expected profit?
Below £1,000 → trading allowance may apply. Above → file SA. - Is your total tax bill likely to exceed £1,000?
Yes → HMRC will require payments on account next January. - Do you also have employment income?
Yes → your PAYE tax code should be checked against your total income. - Do you have unusual reliefs (pension, marriage allowance, gift aid)?
Include them on the return — the calculator here doesn't.
Sources & official references
Every rate and threshold in this guide traces back to a published UK official source. All updated for the 2026/27 tax year.
Related on FreelanceToolkit UK
Your numbers
Your estimate
Income tax breakdown
| Band | Rate | Amount in band | Tax |
|---|
National Insurance (Class 4)
| Band | Rate | Amount | NI |
|---|
How this calculator works
Taxable profit = turnover − allowable expenses. Add any PAYE salary to get your total taxable income. The personal allowance is £12,570 in 2026/27, but it's reduced by £1 for every £2 you earn above £100,000 — so it's £0 once you hit £125,140.
Income tax bands (England, Wales & NI, 2026/27)
- Basic rate (20%): £12,571 – £50,270
- Higher rate (40%): £50,271 – £125,140
- Additional rate (45%): over £125,140
Class 4 National Insurance
- 6% on profits between £12,570 and £50,270
- 2% on profits above £50,270
Class 2 NI
No longer compulsory above the Small Profits Threshold — your State Pension entitlement is preserved automatically. You can choose to pay £3.65/week (2026/27) voluntarily if you fall below.
Worked examples
£52,000 profit (typical mid-career freelancer)
Inputs: turnover £60,000, allowable expenses £8,000. No PAYE, no pension, no student loan.
Result: income tax £8,232, Class 4 NI £2,297, take-home £41,471.
Why: profit £52,000 minus personal allowance £12,570 = £39,430 taxable. £37,700 at 20% basic rate, then £1,730 spills into higher rate at 40%. Class 4 NI is 6% on the full basic-rate band plus 2% on the £1,730 above £50,270.
£110,000 profit (personal-allowance taper kicks in)
Inputs: turnover £120,000, expenses £10,000.
Result: income tax £33,432, Class 4 NI £3,457, take-home £73,111.
Why: above £100,000 the personal allowance reduces by £1 for every £2 of extra income. At £110,000 the allowance tapers to £7,570, so taxable income is £102,430: the first £37,700 at 20% and the remaining £64,730 at 40%. The basic-rate band is measured on taxable income, so it ends at £45,270 of profit here, not £50,270. Effective marginal rate above £100k is 60% (40% income tax plus 20% lost allowance).
£18,000 profit (basic-rate only)
Inputs: turnover £20,000, expenses £2,000.
Result: income tax £1,086, Class 4 NI £326, take-home £16,588.
Why: profit £18,000 minus allowance £12,570 = £5,430 taxable at 20%. Class 4 NI is 6% on the £5,430 above the lower profits limit. No higher-rate spillover.
Frequently asked questions
Is this calculator HMRC-approved?
No third-party calculator is "HMRC-approved" — HMRC don't endorse external tools. The figures here use HMRC's published rates and bands for 2026/27 and are cross-checked against worked examples. For your actual return, file through HMRC's Self Assessment portal or paid software.
Does it handle the personal-allowance taper above £100,000?
Yes. The allowance reduces by £1 for every £2 of income above £100,000, hitting £0 at £125,140. The calculator applies this taper automatically and shows the reduced allowance in the breakdown.
What about Scottish income tax bands?
Select "Scotland" in the Region dropdown. Scottish income tax has six bands (Starter, Basic, Intermediate, Higher, Advanced, Top) — Class 4 NI is the same UK-wide.
Should I include pension contributions?
Yes — enter the net amount you paid (e.g. £80 if you wrote a £80 cheque). The calculator grosses it up by 25% to reflect basic-rate relief at source, then extends your basic-rate band by that gross amount. Higher-rate taxpayers get the extra relief through Self Assessment.
What's the difference between Class 2 and Class 4 NI?
Class 2 is a flat £3.65/week in 2026/27 and is no longer compulsory above the Small Profits Threshold (£7,105 in 2026/27) — you get the State Pension qualifying year automatically. Class 4 is the profit-based contribution: 6% between £12,570 and £50,270, then 2% above.
Does it cover student loans?
Yes — Plans 1, 2, 4 (Scotland), 5, and Postgraduate. Each plan has its own threshold and rate. Repayments are deducted on top of your tax/NI.
What's not included?
Dividends, capital gains, payments on account, marriage allowance transfer, gift aid relief, child benefit charge, IR35 deemed-employment scenarios, and VAT. For limited-company directors, see our limited-company take-home calculator. For VAT-registered freelancers, see the Flat Rate Scheme calculator and the VAT return calculator.
Will my tax-deductible expenses reduce my mortgage borrowing?
Yes — UK lenders assess sole traders on net profit (SA302), so allowable expenses you've claimed reduce the income figure lenders see. If you're 12+ months from a mortgage application, talk to your accountant about which expenses are optional (e.g. capital-purchase timing). See our freelancer mortgage guide for the full income-assessment picture.
Should I incorporate as a limited company to reduce my tax?
Not automatically. On 2026/27 rates, if you draw out all your profit, a sole trader usually keeps the same or more than a limited-company director once employer NI, corporation tax, dividend tax (10.75% / 35.75% / 39.35%) and accountancy fees are included. A company can come out ahead when you retain profit in it or make employer pension contributions. Use our sole trader vs Ltd calculator with your own figures.
This calculator is general guidance based on UK rates for the 2026/27 tax year. It is not personal tax advice. For complex situations (CIS, IR35, capital allowances, dividends, second jobs) consult a qualified accountant.