AUS GST CALCULATOR
Add it, strip it, or work backwards from the GST itself — at 10%.
How to use this calculator
If a price includes GST, this calculator will tell you how much.
If a price excludes GST, this calculator will tell you how much GST to add.
If you have the GST portion, this calculator will work out both the GST inclusive and GST exclusive price for you.
Simply enter your figure in the appropriate row and let the calculator do its thing!
A worked example
Australia's GST is 10% - lower than New Zealand's 15%, and the round number makes it a bit friendlier to work with.
Adding it is simple: $100 plus 10% is $110. Extracting it from a GST-inclusive price is where the neat trick lives - just divide by 11. So on a $110 price that includes GST, the GST portion is exactly $10. On a $220 price, it's $20. The calculator handles both directions for you.
Put your amount in above, and choose whether you're adding GST or pulling it out.
Quick note: Australia's GST has been 10% since 2000, so the rate and the "divide by 11" trick are rock solid. The AUD $75,000 registration threshold and the GST-free categories can move, so check ato.gov.au if you're running a business over there.
What most people get wrong about Australian GST
The first thing Kiwis and Aussies both slip on is mixing up the rates. Australia is 10%, New Zealand is 15% - so you can't reuse the same maths across the Tasman. And to find the GST inside an Australian inclusive price, the shortcut is divide by 11 (not by 23 and times 3, which is the New Zealand method).
For business, the registration threshold in Australia is higher too: AUD $75,000 of turnover, versus NZ's $60,000. Below that, registering for GST is optional; above it, you must.
The other difference worth knowing is that Australia carves out more exceptions. A range of basic foods, some health and medical items, and certain education costs are "GST-free," which isn't how New Zealand's much broader, simpler GST works. So if you're selling into Australia, don't assume every product carries the 10% - check whether what you're selling is one of the GST-free categories first.
This calculator and page are general information only and not financial advice. Everyone's circumstances will vary - always do your own research and consult your own financial professionals before making decisions.