2026/27 Tax Year

Sole Trader Tax Calculator

Turn turnover and business costs into a realistic view of taxable profit, self-employed tax drag, and how much cash you may want to keep aside before the Self Assessment bill lands.

Scope: this is a simple England and Northern Ireland model for a sole trader using 2026/27 income tax and Class 4 NIC rates. It does not file your return, and it does not include VAT, CIS, or capital allowances planning.

Your inputs

Estimated take-home from your self-employed profit
£0 After income tax, Class 4 NICs, and any student loan drag.
Taxable profit£0
Income tax and Class 4 NICs£0
Student loan from the business income£0
Suggested reserve to hold back£0

What this means

You have a straightforward profit profile here, so the main task is simply ring-fencing the tax reserve before it gets mixed into day-to-day cash flow.

Why is this based on profit, not turnover?

Self-employed tax is charged on profit after allowable business costs, not on revenue. Turnover tells you how much cash came in; profit is the number the tax system usually cares about.

Why do people get caught out by payments on account?

Once your Self Assessment bill is large enough, HMRC can ask for advance payments towards the following year as well. This calculator focuses on the underlying annual tax drag, so use the reserve figure as a minimum cash buffer rather than a promise about your exact January payment.

What about Class 2 National Insurance?

Since April 2024, most sole traders no longer pay mandatory Class 2 NICs, but small profits can still matter for your National Insurance record. If profits are very low, it can be worth checking whether voluntary Class 2 or another qualifying year route matters for State Pension purposes.

My scenarios