How to Add and Remove VAT, GST and Sales Tax
Understand the formulas with fictional examples and your own local inputs, without relying on a fixed tax year.
Add or remove VAT, GST or sales tax
Enter the rate applicable to your transaction. To add tax, multiply the net price by rate ÷ 100, then add that tax to the net price. To remove included tax, divide the gross price by (1 + rate ÷ 100). Subtracting the percentage directly from the gross price gives the wrong result.
Worked example with a fictional 15% rate
A net price of 200 units plus 15% tax gives tax of 30 and a total of 230. Starting with an inclusive price of 230, dividing by 1.15 recovers the net price of 200. A zero rate leaves the price unchanged.
Which rate should I enter?
Use the percentage confirmed for your country, region, product and transaction date. This calculator stores no country rate tables and does not decide whether an item is taxable, exempt or eligible for a reduced rate. Tax is rounded to two decimal places; local invoice rules and currencies may require different rounding.
The currency field changes the display label only. Use the same currency throughout; it does not convert money. This models one percentage tax, not multiple compounding taxes or a complete tax return.