Sales Tax & GST Calculator
Calculate tax-inclusive price and tax amount for any rate.
How to calculate sales tax or GST
Tax amount = Price × (rate% ÷ 100)
Price incl. tax = Price × (1 + rate% ÷ 100)
Example: $450 + 15% GST → Tax = $67.50. Total = $517.50.
Common tax rates by country
| Country / Region | Rate | Tax name |
|---|---|---|
| New Zealand | 15% | GST |
| Australia | 10% | GST |
| United Kingdom | 20% | VAT (standard) |
| European Union | 17–27% | VAT (varies by country) |
| Canada | 5% + provincial | GST / HST / PST |
| USA | 0–10.25% | Sales tax (varies by state) |
To find the pre-tax price from a tax-inclusive price: Divide by (1 + rate/100). For example, $517.50 including 15% GST: 517.50 ÷ 1.15 = $450 pre-GST.
Frequently asked questions
New Zealand GST is 15%. To add GST: multiply the pre-GST price by 1.15. To find GST in a GST-inclusive price: divide by 1.15, then subtract from the original. Or: multiply the GST-inclusive price by 3 ÷ 23 to get the GST component.
Divide the GST-inclusive price by (1 + rate/100). For 15% GST: price ÷ 1.15. For example, $230 including 15% GST: 230 ÷ 1.15 = $200 pre-GST. The GST component is $30.