How to use the gst calculator
- 1Choose Australia or New Zealand.
- 2Choose whether you have a price before GST or a total that includes GST.
- 3Enter the amount.
- 4Read the GST and the total, or the price before GST.
GST in Australia
Australia charges GST at a single rate of 10%. Many basic foods, most health and education services and exports are GST-free. Businesses with a GST turnover of A$75,000 or more must register, and registered businesses include GST in their prices and claim credits for GST they pay.
To find the GST inside a GST-inclusive price, divide by 11. On a $110 total, the GST is $10 and the price before GST is $100.
GST = Price × 10 ÷ 100 GST in a total = Total ÷ 11
GST in New Zealand
New Zealand charges GST at 15% on most goods and services. Exports and some supplies are zero-rated, while financial services and residential rent are exempt. Businesses must register once turnover reaches NZ$60,000 in 12 months.
The GST inside a GST-inclusive price is three twenty-thirds of it (15 ÷ 115). On a $115 total, the GST is $15 and the price before GST is $100.
GST = Price × 15 ÷ 100 GST in a total = Total × 3 ÷ 23
Do not take 10% or 15% off a total
GST is charged on the price before GST, which is smaller than the total. Taking 10% off a $110 total gives $99, but the real price before GST is $100. The calculator shows the correct figure and the common wrong one side by side.
About the rates
Rates come from the Australian Taxation Office and Inland Revenue New Zealand, and the date we last checked them is shown below the calculator. Confirm whether your product is taxable, GST-free or exempt before you invoice.
Worked example
A Sydney consultant receives a $3,300 payment that includes GST and needs to record the GST.
| Total including GST | $3,300.00 |
| GST (÷ 11) | $300.00 |
| Price before GST | $3,000.00 |
| Wrong answer if you take 10% off | $2,970.00 |
The consultant records $300 of GST and $3,000 of income, not $330 and $2,970.
Frequently asked questions
How do I calculate GST in Australia?
How do I work out GST backwards in New Zealand?
Do I charge GST to overseas customers?
Is Canadian GST the same?
GST calculators by country
Each page is pre-filled with that country's current rates and explains how the tax works there.