Self-employed tax calculator

Estimate your Income Tax, National Insurance and what you actually take home from self-employment. Results update as you type. Free, and no sign-up needed.

MoneyGlass provides educational calculations and estimates. It does not provide regulated financial, mortgage, credit, tax or investment advice.

Results depend on the information and assumptions entered by the user. Confirm important decisions with an appropriately authorised professional.

Your self-employment

Income for the year

Everything you invoice, before expenses.

Allowable expenses

Costs incurred wholly for the business. Tax is charged on what's left, not on turnover.

Other income already taxed

A salary alongside this, taxed through PAYE. It matters: your profit stacks on top of it, so it's taxed at your highest rate rather than starting again from zero.

Where you pay tax

Scotland sets its own income tax bands. National Insurance is the same UK-wide.

Your estimated bill for 2026/27

Taxable profit

£32,000

Income minus expenses

Tax and NI

£5,052

15.8% of your profit

You keep

£26,948

After tax and NI

Income tax on your profit: £3,886
Class 4 National Insurance: £1,166
Class 2 National Insurance: £0
Total: £5,052

Personal allowance used: £12,570.

What to put aside

From every £100 you invoice

£16

Rounded up — being slightly over is harmless, being under isn't.

Or per month

£420.98

A standing order into a separate account you don't touch

When HMRC wants it

Last year's tax bill

Leave blank if this is your first year. It decides whether payments on account apply.

Add last year's tax bill to see whether payments on account apply. Nothing has gone toward this year yet, so the whole bill falls due in January — along with the first instalment toward next year.

31 January — this year's bill plus the first instalment toward next year: £7,578
31 July — second instalment toward next year: £2,526

That January figure is the one that catches people out: it settles the year just ended and pays toward the next one, in the same week. Both instalments toward next year are half of this year's bill — so if you've had a good year, they go up.

Payments on account also don't apply if more than 80% of last year's tax was already collected at source, usually through a tax code. MoneyGlass can't see how your tax was collected, so it doesn't assume either way.

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