Based on 2025/26 England, Wales & Northern Ireland rates for a sole trader with no other income. Excludes Class 2 NI, student loan repayments, the High Income Child Benefit Charge and Scottish rates. Payments on account apply once your bill is over £1,000. Not tax advice.
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This calculator estimates the Income Tax and Class 4 National Insurance a self-employed tradesperson pays, and what is left as take-home. Enter your annual profit — that is your income after allowable business expenses, not your turnover — and it works out the tax, the NI and the money you actually keep.
It is for sole traders trying to answer the question every tradesperson asks at some point: if I make this much, how much is really mine? Seeing the tax and NI side by side helps you set money aside through the year instead of being caught out by a Self Assessment bill in January.
The maths follows HMRC's bands for 2025/26. Your personal allowance is tax-free, the next slice is taxed at 20%, then 40% higher up, with Class 4 NI charged separately on your profit. The calculator applies each band in turn and adds the two together to show your total liability.
Income Tax = taxable profit stepped through 20% / 40% / 45% bands; Class 4 NI = 6% on profit £12,570–£50,270 + 2% above; Take-home = profit − tax − NI
Taxable profit is your profit minus the personal allowance (which tapers away above £100,000). Income Tax is charged at 20% on the basic-rate band, 40% on the higher-rate band and 45% above £125,140. Class 4 National Insurance is a separate charge on profit — 6% between £12,570 and £50,270 and 2% on anything above. Take-home is your profit less both.
Type your profit after allowable expenses — materials, van, tools, insurance, phone and the rest — not your turnover. Tax and NI are charged on profit, so expenses you have not claimed are tax you are overpaying.
The default £12,570 is the standard 2025/26 personal allowance. Leave it unless you have another job or income using part of it, in which case reduce it. Above £100,000 profit the tool tapers it automatically.
The calculator shows your Income Tax, your Class 4 National Insurance and the combined total you owe HMRC for the year.
It shows your take-home after tax and your effective tax rate, plus the size of each payment on account — the advance instalments HMRC asks for once your bill is over £1,000.
The figure to enter is profit, not turnover. If you turn over £60,000 but spend £15,000 running the business, you are taxed on £45,000. Keeping good records and claiming every allowable expense is the single biggest lever on your tax bill — this calculator only reflects what you tell it your profit is.
Payments on account catch new sole traders out. Once your Self Assessment bill passes £1,000, HMRC asks for it plus a 50% advance toward next year in January, and another 50% in July. Your first January bill can therefore be around 150% of a single year's tax, so set money aside from day one.
This is an estimate on 2025/26 England, Wales and Northern Ireland rates for someone with no other income. It excludes Class 2 NI, student loan repayments, the High Income Child Benefit Charge, pension contributions and Scottish income tax bands, which differ. It is a guide, not tax advice — confirm with an accountant or HMRC.
Based on 2025/26 England, Wales & Northern Ireland rates for a sole trader with no other income. Excludes Class 2 NI, student loan repayments, the High Income Child Benefit Charge and Scottish rates. Payments on account apply once your bill is over £1,000. Not tax advice.
You pay Income Tax and Class 4 National Insurance on your profit — your income after expenses. On a £40,000 profit for 2025/26 that is roughly £5,486 Income Tax plus £1,646 Class 4 NI, so about £7,130 in total, leaving around £32,870. Enter your own profit above for a figure tailored to you.
Profit. You deduct your allowable business expenses — materials, tools, van, insurance, use of home, and so on — from your turnover first, and are taxed only on what is left. This is why keeping receipts and claiming everything you are entitled to matters so much.
They are advance instalments toward your next tax bill. Once your Self Assessment liability is over £1,000, HMRC asks you to pay it in full by 31 January plus half again as a payment on account, then the other half by 31 July. It brings you onto a pay-as-you-go footing but makes the first year's January bill much larger.
For most people, no. From 2024/25 Class 2 NI is no longer charged if your profits are above the small profits threshold — you still build your State Pension entitlement without paying it. This calculator therefore shows only Class 4 NI. If your profits are very low you may choose to pay Class 2 voluntarily.
No. Scotland sets its own income tax bands and rates, which differ from the rest of the UK. This calculator uses the England, Wales and Northern Ireland bands. If you are a Scottish taxpayer, treat the Income Tax figure as indicative only and check the Scottish rates.
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