Sales Tax & VAT Calculator
Add tax to a net price or extract it from a gross one at the rate you enter, line by line with quantities and mixed rates, rounded as invoices are.
The net, tax and gross of an invoice or receipt either way round, with per-line rounding made explicit — arithmetic at your rate, with no jurisdiction’s rules assumed.
Example: 100 net at 20 % is 120 gross; 120 gross at 20 % is 100 net and 20 tax. Three items at 19.99 taxed at 20 % plus one at 45 taxed at 5 % total 119.21, of which 14.24 is tax.
Divide by 1 + r,
never subtract r %.
The two directions, the rounding convention, and why no tax rate lives on this page.
Adding and removing tax
Adding tax to a net amount is net × rate; the gross is net + tax. Taking tax out of a gross amount is the step most often done wrong: the net is gross ÷ (1 + rate), not gross less rate percent — 120 at 20 % contains 20 of tax (net 100), not 24. The page works either way round, on as many lines as you like, each with its own quantity and rate, and shows the blended effective rate of the whole.
Rounding
Invoicing systems usually round the tax on each line to two decimals and add the rounded lines; rounding once on the total can differ by a cent or two, and tax authorities generally accept either as long as it is consistent. The page rounds per line by default and lets you switch it off to see the unrounded arithmetic.
No rates, no rules
Which rate applies, whether an item is exempt, zero-rated or reduced, whether you must register, and how to file are matters of the tax law where you sell, and they change. This page carries none of it: you enter the rate, it does the arithmetic. For compliance questions, ask your accountant or the tax authority. Nothing leaves the browser; the same four anonymous usage counts as the rest of the site apply.
SOURCES
- Tax-inclusive and tax-exclusive arithmetic: gross = net × (1 + r), net = gross ÷ (1 + r) — arithmetic only; rates and rounding conventions are the user’s
Last reviewed 19 September 2026. How results are checked: How we verify.