Follow a taxable price across the row
These examples assume an Australian taxable sale subject to 10% GST. The GST-exclusive amount is the base price; adding 10% of that base produces the GST-inclusive total.
| GST-exclusive price | GST amount | GST-inclusive price |
|---|---|---|
| $50 | $5 | $55 |
| $100 | $10 | $110 |
| $250 | $25 | $275 |
| $500 | $50 | $550 |
| $1,000 | $100 | $1,100 |
Read from left to right when adding GST. When starting with the final price, divide by 1.10 to recover the base, or by 11 to find the GST component. Subtracting 10% of the final price gives a different and incorrect result.
Unpack a $275 inclusive price
$275 ÷ 11 = $25 GST, and $275 ÷ 1.10 = $250 before GST. Adding the two components checks the row: $250 + $25 = $275.
Check the tax treatment first
The chart does not determine registration obligations or whether a supply is taxable, GST-free or input taxed. It also does not calculate input-tax credits, adjustments or a complete activity statement. Apply the arithmetic only after establishing the correct treatment.
Frequently asked questions
Why is GST one-eleventh of the final price?
A 10% taxable price contains 100 parts base price plus 10 parts GST. The GST share is therefore 10 out of 110 parts, or one-eleventh.
Can I use these rows for a GST-free sale?
No. The rows assume 10% GST applies. A GST-free sale has different treatment.