Add 10% GST to a price, or find the GST and the price before GST in a GST-inclusive amount.
This calculator needs JavaScript to run. The sum is simple: to add GST, multiply the price by 1.1. To remove it, divide the GST-inclusive price by 11 to get the GST. For example, $100 plus GST is $110, and $110 includes $10 GST.
Tap a figure to copy it.
Rounded to the nearest cent. This works out GST on one amount. It does not prepare a BAS.
GST rate checked on 2 November 2026.
To add GST, multiply the price before GST by 10 and divide by 100, then add the result to the price. In one step, multiply the price by 1.1. GST on $100 is $10, so the GST-inclusive price is $110.
In the calculator above, choose Add GST and enter the price before GST. For a GST-free sale, choose GST-free (0%) and no GST is added.
To remove GST from a GST-inclusive price, divide the price by 11 to get the GST, then subtract it. On $110, the GST is $10 and the price before GST is $100.
Do not take 10% off the GST-inclusive price: 10% off $110 is $99, not $100, because the GST was worked out on the lower price. In the calculator above, choose Remove GST.
The price before GST, the GST at 10% and the GST-inclusive price.
| Price before GST | GST | Price with GST |
|---|---|---|
| $10.00 | $1.00 | $11.00 |
| $50.00 | $5.00 | $55.00 |
| $100.00 | $10.00 | $110.00 |
| $500.00 | $50.00 | $550.00 |
| $1,000.00 | $100.00 | $1,100.00 |
The GST-inclusive price, the GST it contains (one eleventh) and the price before GST.
| Price with GST | GST | Price before GST |
|---|---|---|
| $10.00 | $0.91 | $9.09 |
| $50.00 | $4.55 | $45.45 |
| $100.00 | $9.09 | $90.91 |
| $500.00 | $45.45 | $454.55 |
| $1,000.00 | $90.91 | $909.09 |
To calculate GST, multiply the price before GST by 10 and divide by 100. On $100, the GST is $10 and the GST-inclusive price is $110.
To add GST, GST = price × 10 ÷ 100 and the GST-inclusive price = price × 1.1. To remove GST, GST = GST-inclusive price ÷ 11 and the price before GST = GST-inclusive price − GST.
Divide the GST-inclusive price by 11 to get the GST, then subtract it. On $110, the GST is $10 and the price before GST is $100. On $100, the GST is $9.09 and the price before GST is $90.91.
A GST-exclusive price is the amount before GST is added. To turn it into a GST-inclusive price, multiply it by 1.1, so $50 becomes $55.
A GST-inclusive price already includes 10% GST. The GST is one eleventh of that price, so a $55 price includes $5 GST.
Because the GST was worked out on the price before GST, which is lower. 10% off $110 is $99, but the price before GST is $100 and the GST is $10.
You’ve got the GST. Now get paid.
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