VAT / GST / Sales Tax Calculator
Add VAT, GST or sales tax to a price, or take it out of a total that already includes tax. Pick a country to start from its standard rate, or type your own.
Your amount
Your result
- Amount before tax
- 0
- Tax
- 0
Total including tax
0
How the calculation works
The tax rate is applied to the price before tax. Going the other way, the tax is already inside the total.
- Adding tax: total = price x (1 + rate / 100). A price of 100 at 20% becomes 120, of which 20 is tax.
- Removing tax: price = total / (1 + rate / 100). A total of 120 at 20% is 100 before tax, so the tax is 20.
A common mistake
Taking 20% off a total of 120 gives 96, not 100. The tax was calculated on the smaller pre-tax price, so you have to divide by 1.20 rather than subtract 20%. This calculator does the division for you.
Showing tax on an invoice
Zap Bill invoices have tax rows with their own rate, and the totals show tax separately from the subtotal. Choosing your country when you set up a workspace fills in a starting rate that you can edit on the profile and on each invoice.
VAT, GST and sales tax calculator FAQ
How do I add VAT or GST to a price?
Multiply the price by 1 plus the rate as a decimal. At 20%, multiply by 1.20, so 100 becomes 120. The difference, 20, is the tax.
How do I take VAT out of a total?
Divide the total by 1 plus the rate as a decimal. At 20%, divide by 1.20, so 120 becomes 100. Subtracting 20% of 120 would give the wrong answer.
What is the difference between VAT, GST and sales tax?
VAT and GST are both charged on sales at each step of the supply chain, and registered businesses can usually reclaim what they pay on their own purchases. US sales tax is generally charged once, at the final sale, and the rate depends on the state and often the locality. The arithmetic of adding or removing a percentage is the same for all three.
Are the country rates up to date?
They are the standard national rates Zap Bill uses as a starting point, and they can change. They do not cover reduced or zero rates, exemptions or regional taxes. Confirm the rate with your tax authority or an accountant, and type it in if it differs.
Can Zap Bill add tax to my invoices for me?
Invoices have tax rows with a rate you set, and the totals show tax separately from the subtotal. Setting your country when you create a workspace fills in a starting rate you can change. You stay responsible for choosing the right rate for each sale.
Put the tax on a real invoice
Create an invoice with tax shown separately from the subtotal, then download it as a PDF. It is free, with no sign-up needed.