GST Calculator Australia
Add 10% GST to a price, or find how much GST is already in a total. The result updates as you type.
Add or remove 10% GST
Dollars and cents, for example 1,250.50
GST formulas
Australian GST is 10% of the price of most goods and services. Which formula you need depends on whether the price you have already includes GST.
Add GST: price excluding GST × 1.1 = price including GST
Remove GST: price including GST ÷ 1.1 = price excluding GST
GST inside a GST-inclusive price: price including GST ÷ 11
The last formula is the quickest way to find the GST in a total. GST is one eleventh of any GST-inclusive price, not one tenth, because the 10% was worked out on the smaller price before GST. The guide to calculating GST shows why.
Adding GST to a price
A $100.00 price excluding GST has GST of $100.00 × 10% = $10.00 added, for a total of $110.00 including GST.
Taking GST out of a price
A $110.00 price including GST contains $110.00 ÷ 11 = $10.00 of GST. The price before GST is $110.00 − $10.00 = $100.00.
When the answer is not a whole number of cents
Take a $250.00 price including GST. $250.00 ÷ 11 = $22.7272…, which rounds to $22.73. The price excluding GST is $250.00 − $22.73 = $227.27.
Half a cent rounds up. GST on a $19.95 price excluding GST is $19.95 × 10% = $1.995, which rounds up to $2.00, so the price including GST is $21.95.
GST on common amounts
Read left to right to add GST. Read right to left to take it out.
| Price excluding GST | GST (10%) | Price including GST |
|---|---|---|
| $10.00 | $1.00 | $11.00 |
| $20.00 | $2.00 | $22.00 |
| $50.00 | $5.00 | $55.00 |
| $100.00 | $10.00 | $110.00 |
| $250.00 | $25.00 | $275.00 |
| $500.00 | $50.00 | $550.00 |
| $1,000.00 | $100.00 | $1,100.00 |
| $2,500.00 | $250.00 | $2,750.00 |
| $10,000.00 | $1,000.00 | $11,000.00 |
How GST is rounded
The ATO says that where GST includes a fraction of a cent, a single taxable sale on a tax invoice is rounded to the nearest cent, with 0.5 of a cent rounded up. This calculator does exactly that. When an invoice has several taxable items there are two accepted ways to round, explained on the invoice GST calculator.
When GST applies
- Taxable sales carry 10% GST. This covers most goods and services sold by a business that is registered for GST, or required to be.
- GST-free sales have no GST in the price. Most basic food, some health, education and childcare services, and exports are GST-free. The seller can still claim GST credits on what it spent to make these sales.
- Input-taxed sales also have no GST in the price, but the seller cannot claim credits. The common examples are financial supplies and residential rent.
This calculator assumes the 10% applies. Check the ATO’s lists if you are unsure about an item, for example its GST food list.
Quick tips
- If a quote says “plus GST”, choose Add GST. If a receipt says “includes GST” or “inc GST”, choose Remove GST.
- Never take 10% off an inclusive price. $110.00 less 10% is $99.00, not $100.00.
- Several items on one invoice? Use the invoice calculator so rounding and GST-free items are handled correctly.
- Lodging a BAS? The BAS calculator estimates 1A and 1B from your sales and purchases.
Frequently asked questions
What is the GST rate in Australia?
GST is 10% on most goods and services sold or consumed in Australia. Some things carry no GST, such as most basic food, some health and education services and exports (the ATO calls these GST-free sales).
How do I add 10% GST to a price?
Multiply the price excluding GST by 1.1. For example, $100.00 × 1.1 = $110.00. The GST is the difference, $10.00.
How do I work out the GST in a price that already includes GST?
Divide the GST-inclusive price by 11. A $110.00 receipt contains $110.00 ÷ 11 = $10.00 of GST, so the price before GST was $100.00. The reverse GST calculator does this for you.
Why is the GST in a total not 10% of the total?
The 10% is charged on the price before GST, which is the smaller number. In a $110.00 total, 10% of $110.00 would be $11.00, but the GST is $10.00 because it was worked out on $100.00. That is why the GST in an inclusive price is one eleventh, not one tenth.
Do I have to charge GST?
If you are registered for GST, or required to be, you charge GST on your taxable sales. You must register when your GST turnover is $75,000 or more ($150,000 for non-profit organisations), or if you provide taxi or limousine travel (including ride-sourcing) at any turnover. Otherwise registering is optional. See who needs to register.
Can I use this calculator for New Zealand?
No, New Zealand GST is 15%, not 10%. Use the NZ GST calculator instead.
Is the amount I type saved or sent anywhere?
No. The calculation runs in your browser and nothing you type on this page is sent to our servers or stored. See the privacy policy.
Sources
- ATO: How GST works (10% rate, GST-free sales, what registered businesses do)
- ATO: Tax invoices (rounding of GST, the 1/11 statement)
- ATO: GST-free sales
- ATO: Registering for GST ($75,000 and $150,000 thresholds)
General information only, not tax advice. Check your situation with the ATO or a registered tax or BAS agent.