Sales Tax / GST / VAT Calculator
Add sales tax, GST, or VAT to a price, or find the tax hidden inside a tax-inclusive price.
Sales Tax / GST / VAT
Add tax to a price, or work out the tax inside a tax-inclusive price.
Price including tax
120.00
- Tax: 20.00
- Price before tax: 100.00
Enter the tax rate yourself — no rates are built in. Rates differ by place and by item.
How it works
Enter an amount and a tax rate, then choose whether the amount is before tax (add tax) or already includes tax (remove tax).
To add tax, the rate is applied to the pre-tax amount. To remove it, the tax-inclusive amount is divided by 1 plus the rate to recover the pre-tax amount; the difference is the tax.
Enter the rate that applies to your purchase — no rates are built in, and they vary by place and by item. This uses a single flat rate; it does not handle multiple stacked taxes.
Formula
add tax: tax = amount × (rate ÷ 100), total = amount + tax
remove tax: pre-tax = total ÷ (1 + rate ÷ 100), tax = total − pre-tax
Worked example: Adding 20% tax to 100 gives 120.00 (tax 20.00); removing 20% tax from 120 leaves 100.00