To add 10% GST, multiply the price by 1.10. To remove it from a total, divide by 1.10.
TL;DR: Adding GST is price × 1.10 at the Australian rate. Removing it is total ÷ 1.10, and the GST portion equals the total ÷ 11. The GST calculator lets you pick the country rate and does both directions.
Adding and removing GST
A $200 sale before tax at Australia’s 10% rate becomes $220, with $20 of GST. To go the other way, divide the $220 total by 1.10 and you are back to $200.
There is a neat check at 10%. The GST inside a total is just the total divided by 11. A $220 total ÷ 11 = $20 of GST. The GST calculator shows the tax amount separately so you can confirm it.
Rates by country
The rate you multiply by depends on where you are:
- Australia: 10%
- New Zealand: 15%
- Singapore: 9%
- Canada: 5% federal GST, plus provincial portions in HST provinces. Nova Scotia’s HST is now 14%.
Canada is the fiddly one, since the combined rate changes by province. Pick the province in the tool and it applies the right total.
India’s GST 2.0 slabs
India restructured its system on 22 September 2025. There are now four slabs: 0%, 5%, 18% and 40%. The old 12% and 28% bands are gone. Most everyday goods sit at 5% or 18%, and the 40% band covers a narrow set of items.
If you are pricing for India, choose the slab that matches the goods rather than assuming a single national rate.