Tax Calculator (GST, VAT, Sales Tax)
Add GST, VAT or sales tax to a price, or take it out of a price that already includes it, at any rate. See the amount before tax, the tax and the total.
Runs in your browser. Your data is not uploaded.How our tools work
The GST, VAT or sales tax rate that applies.
This calculator does the arithmetic only. Tax rules, rates and rounding vary by country and product; it isn’t tax advice.
How do I add or remove tax from a price?
To add tax, multiply the price by the rate: 18% tax on 100 is 18, so the total is 118. To remove tax from a price that includes it, divide by one plus the rate: 118 ÷ 1.18 = 100, so the tax is 18. Subtracting 18% of 118 would be wrong. Enter any amount and rate.
- Choose whether your price is before tax or already includes tax.
- Enter the amount and the tax rate, such as 18 for 18% GST or 20 for 20% VAT.
- Read the amount before tax, the tax and the total including tax.
Formulas & Methods
Add tax
Example: 250 at 20% VAT: tax 50, total 300
Remove tax
Example: 300 at 20%: 300 ÷ 1.2 = 250, tax 50
Key features
Add or remove tax
Work from a price before tax or from a total that already includes it.
The correct reverse formula
Removing tax divides by (1 + rate) instead of subtracting the rate from the total, which would take off too much.
Any rate, any country
Enter the GST, VAT or sales tax rate that applies to you. No country’s rules are assumed.
Why you can’t just subtract the percentage
Tax is calculated on the price before tax, not on the total. At 18%, a 100 price becomes 118. Taking 18% of 118 gives 21.24, which is more than the 18 that was added, so subtracting it leaves 96.76 instead of 100. Dividing by 1.18 reverses the calculation exactly.
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Frequently Asked Questions
Can I enter a rate with decimals, such as 8.875%?
Yes. Any rate from 0 to 100 works, with decimals: 8.875 for a combined state and local sales tax, or 5.5. Use a point or a comma for the decimal, and the % sign is optional.
Is this for a specific country?
No. It works with any rate you enter. It doesn’t know any country’s tax rules, exemptions or rounding, and it isn’t tax advice: check which rate applies with your tax authority or an accountant.
How do I find the tax rate from two prices?
Divide the price including tax by the price before tax, subtract 1 and multiply by 100. For 115 and 100: 115 ÷ 100 = 1.15, so the rate is 15%.
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