United Kingdom Tax year 2026/27
Rules checked against GOV.UK · updated 18 September 2026MethodologyReport a mistake
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Self-employed tax calculator 2026/27

Work out income tax and National Insurance on self-employed profit, and see what is left once your allowable expenses come off.

Everything the business invoiced or took this tax year, before costs.
Where do you live?
What you keep from your profit
£36,568.20
from £45,000 of profit, after income tax and National Insurance, or £3,047.35 a month
Income tax£6,486.00
Class 4 National Insurance£1,945.80
Effective rate on profit18.7%
Set aside £702.65 a month. That covers the £8,431.80 of income tax and National Insurance this profit owes, so the bill is already saved for when it is due.
How it adds up

Every step of your self-employed tax

Worked calculationrules v2026.18 · profit basis
Turnover£55,000.00
Allowable expenses−£10,000.00What the business spent
Profit£45,000.00
Personal Allowance−£12,570.00Tax-free
Profit taxed£32,430.00
Basic rate 20% on £32,430.00£6,486.00Income tax
Class 4 6% on £32,430.00£1,945.80Above £12,570
Class 2£0.00Treated as paid
What you keep£36,568.20
Putting money by

What to keep back for the bill

Tax and National Insurance a year£8,431.80
To set aside each month£702.65
Rules v2026.18 · checked against GOV.UK on 18 September 2026Two independent checks on every rate · 393 of 418 hand-verified cases, all passing, beside 43,041 generated · How we calculate · Changelog
Payroll-grade
Questions

Common questions

How much tax will I pay on self-employed profit in 2026/27?

On £45,000 of profit: £6,486.00 of income tax and £1,945.80 of Class 4 National Insurance, which is £8,431.80 in total and leaves £36,568.20. That is an effective rate of 18.7% on the profit.

Do I still pay Class 2 National Insurance?

Not as a bill. Profits of £7,105 or more are treated as having paid Class 2, so you get the qualifying year without paying anything. Below that threshold you can pay it voluntarily at £3.65 a week to keep your record going.

What counts as an allowable expense?

Costs incurred wholly and exclusively for the business: stock, tools, software, business travel, professional fees and a share of the cost of working from home. Personal spending does not count, and neither does anything you would have paid anyway.

SourcesSelf-employed National Insurance rates — GOV.UKIncome Tax rates and Personal Allowances — GOV.UK

MyNetIncome gives estimates, not tax or financial advice. Figures follow HMRC and Scottish Government rules for 2026/27; your payslip can differ because of your tax code, pay dates, benefits in kind or pension scheme. Not affiliated with or endorsed by HMRC. Contains public sector information licensed under the Open Government Licence v3.0.