Self-employed tax calculator — profits to take-home, properly

Income tax on your profits (rest-of-UK or Scottish bands) plus Class 4 National Insurance at 6% between £12,570 and £50,270 and 2% above — the same band functions the Hundred Summers app charges in its projections, with the Class 2 abolition and payments-on-account timing explained rather than skipped. Your figures never leave your browser.

The self-employment tax stack

Profits — turnover minus allowable expenses — bear ordinary income tax, then Class 4 NI on top. The NI is the quiet advantage of self-employment: 6% against an employee's 8%, and no employer NI in the chain at all. The calculator shows the gap. What self-employment lacks is an employer pension: no auto-enrolment, no matched contributions — a SIPP contribution reduces the income-tax line here (though not Class 4) and full relief still applies.

The engine behind this page is the same one the Hundred Summers app uses to project a self-employed career year by year — profits growth, pension relief, the State Pension your credited years buy, and retirement funded from what you build. Related: the employee take-home calculator for comparing a salaried offer, and the carry-forward calculator for catch-up contributions in a good year.