GST Calculator
Calculate GST-inclusive or GST-exclusive amounts at any tax rate.
Total (incl. GST)
1,180
How It Works
- 1Choose whether to add or remove GST.
- 2Enter the amount and GST rate.
- 3View the base amount, GST and total.
Features
- Add GST to a base amount
- Remove GST from an inclusive amount
- Any custom tax rate
Privacy
All calculations happen instantly in your browser. Nothing you enter is ever sent anywhere.
About GST Calculator
Adding GST multiplies the base amount by (1 + rate / 100) to get the tax-inclusive total. Removing GST works in reverse: dividing the inclusive total by (1 + rate / 100) gives the base amount, and subtracting that from the total gives the GST portion. It's the same arithmetic used for VAT and general sales tax elsewhere, just under a different name.
This comes up regularly for freelancers and small businesses working out the tax component of a quoted price, anyone checking a receipt or invoice adds up correctly, or cross-border shoppers used to prices displayed as either tax-inclusive or tax-exclusive depending on the country.
The calculator assumes a single flat rate. Many jurisdictions apply multiple rates to different categories of goods and services (standard, reduced, zero-rated) or combine state and federal taxes, and this simple version doesn't model those layered cases — for anything beyond one flat rate, each component needs to be calculated separately.