Use this custom GST calculator when your country or rate is not listed on the website. Enter any GST percentage to calculate the GST amount, add GST to a tax-exclusive price, or remove GST from a tax-inclusive price.
How to use the custom GST calculator
- Enter the GST rate you want to calculate.
- Enter one known value: the GST-exclusive price, GST amount or GST-inclusive price.
- The calculator will determine the other two values automatically.
The calculator performs the arithmetic only. Whether a particular rate applies depends on the country, type of supply and current tax rules.
Custom GST calculation formulas
For a GST rate of R%:
- GST amount = GST-exclusive price × R ÷ 100
- GST-inclusive price = GST-exclusive price × (1 + R ÷ 100)
- GST-exclusive price = GST-inclusive price ÷ (1 + R ÷ 100)
For example, at 12%, a tax-exclusive price of 100 produces a GST amount of 12 and a GST-inclusive price of 112.