VAT, GST & Sales Tax Calculator
Add tax to a net amount or extract the net amount and tax from a tax-inclusive total.
For reference only — not investment or tax advice. Confirm the applicable rate and rules before filing or invoicing.
Every calculation runs in your browser — the figures you enter never leave your device.
FAQ
How is tax added or extracted?
To add tax, multiply the net amount by the rate and add it to the net amount. For example, 100 at 20% gives 20 in tax and 120 including tax. To extract tax from an inclusive total, divide the total by 1 plus the rate as a decimal, then subtract that net amount from the total.
Why can’t I subtract 20% from a tax-inclusive total?
The tax rate is a percentage of the net amount, not the tax-inclusive total. A total of 120 at 20% contains 20 in tax because 120 ÷ 1.20 = 100, not because 20% is subtracted from 120.
What does this calculator leave out?
It calculates one amount at one rate. It does not select a rate, determine tax jurisdiction, split taxes, apply exemptions, rounding rules, thresholds, discounts or invoice-specific requirements. Check the rules that apply to your transaction.