Free Australian business utility
Add or split GST without the spreadsheet detour.
Enter one Australian dollar amount, choose how it is quoted, and see the 10% GST component in seconds. Your amount stays in this browser.
1 · Start with the amount you have
Is GST already in the price?
GST is 10% of the amount before GST.
Use the result carefully
A calculation is not a GST decision.
Taxable supplies. The 10% and 1/11 formulas apply to the taxable part of a supply. GST-free, input-taxed, mixed, export, and other special treatments can produce a different result.
Registration. The ATO says GST registration generally applies once GST turnover reaches A$75,000, with different rules for some organisations and activities. Check the current official guidance for your position.
Records. This tool does not create a tax invoice, determine your GST liability, or prepare a BAS. It is a local arithmetic aid, not tax advice.
Official references
Verify the treatment before you rely on it.
Australian Taxation Office guidance explains that GST is 10% of the value of a taxable supply, which is equivalent to 1/11 of a GST-inclusive price for that taxable part.