How do I remove GST from $110?

$110 ÷ 11 = $10 GST. Price excluding GST = $100.

How do I add GST to $100?

$100 × 1.1 = $110 including GST.

GST is 1/11th of a GST-inclusive total (because $10 is 1/11 of $110), not 1/10th of it.

Calculator · rate unchanged since 2000

Add 10% GST to a price, or remove GST from a total (the "divide by 11" rule). Australia's GST rate has been a flat 10% since 1 July 2000.

Amount (AUD) The price you're working from e.g. $110 (incl. GST) or $100 (excl. GST)

Remove GST (amount includes GST) Add GST (amount excludes GST)

Calculations run in your browser. Nothing is sent.

Australian GST is a flat 10%. Some goods/services are GST-free or input-taxed, this tool assumes a standard taxable supply. Reference: ATO GST.

How do I remove GST from $110?: $110 ÷ 11 = $10 GST. Price excluding GST = $100.
How do I add GST to $100?: $100 × 1.1 = $110 including GST.
Why divide by 11 and not 10?: GST is 1/11th of a GST-inclusive total (because $10 is 1/11 of $110), not 1/10th of it.