Remove GST
Your price already includes GST.
- GST =
- Total ÷ 11
- Amount ex GST =
- Total ÷ 1.10
Example: $330.00 ÷ 11 = $30.00 GST, so the amount excluding GST is $300.00.
Australian GST at 10%
Remove GST Calculator
Use this calculator when a price already includes GST and you need to know how much of it is GST, for a receipt, an expense claim or your BAS. Type the GST-inclusive amount and you'll see the GST and the amount excluding GST straight away.
Last reviewed 8 November 2026 by Simsim.
Amount excluding GST
$0.00
Enter an amount to see the GST.
Add GST: amount × 1.1 = price including GST.
Remove GST: price ÷ 11 = GST included.
For general information only. GSTCal is not affiliated with the Australian Taxation Office or any government agency, and does not give financial, legal or tax advice. Check how GST applies to your situation with the ATO or a registered tax agent.
The formula
How to remove GST from a price
Divide the GST-inclusive price by 11 to find the GST. Subtract that from the price to get the amount excluding GST. Or divide the price by 1.1 to get the ex-GST amount directly.
For a $330 bill: $330 ÷ 11 = $30 GST, and $330 − $30 = $300 excluding GST. The same answer comes from $330 ÷ 1.1 = $300.
Why you can't just take 10% off
GST is 10% of the price before GST, not 10% of the total. Taking 10% off $110 gives $99, but the price before GST was $100. That's why the GST in a GST-inclusive price is one-eleventh, about 9.09%, of the total.
When you need to remove GST
Businesses registered for GST can usually claim a GST credit for the GST included in what they buy for the business, so they need the GST figure from each receipt. Removing GST is also how you find the ex-GST cost of something for budgets, quotes and markups.
Check the receipt first. Some items, such as most basic food, are GST-free, so a GST-inclusive total may contain less GST than one-eleventh, or none.
Worked examples
Calculated with the same rules as the calculator above.
| Amount | GST included | Amount ex GST |
|---|---|---|
| $11.00 | $1.00 | $10.00 |
| $50.00 | $4.55 | $45.45 |
| $99.95 | $9.09 | $90.86 |
| $110.00 | $10.00 | $100.00 |
| $330.00 | $30.00 | $300.00 |
| $1,100.00 | $100.00 | $1,000.00 |
| $2,750.00 | $250.00 | $2,500.00 |
| $11,000.00 | $1,000.00 | $10,000.00 |
Remove GST Calculator questions
How much GST is in $100?
A GST-inclusive price of $100 contains $9.09 GST. The amount excluding GST is $90.91.
Why divide by 11 to find the GST?
A GST-inclusive price is 110% of the original price: 100 parts of price and 10 parts of GST. GST is 10 of those 110 parts, which is one-eleventh.
Can I claim back the GST I've paid?
If your business is registered for GST, you can generally claim a GST credit for the GST in purchases you use for the business, as long as you hold a valid tax invoice where one is needed. Individuals who aren't running a business can't claim GST back, although travellers may be able to claim some through the Tourist Refund Scheme.