Australia · GST 10%
Add or remove GST from any amount. Built for invoicing, quotes and BAS prep, accurate to the cent.
Breakdown
GST (Goods and Services Tax) is a flat 10% tax applied to most goods and services sold in Australia. If a price is GST-exclusive, multiply by 1.1 to get the GST-inclusive total. If a price already includes GST, divide by 11 to find the GST component, not by 10, which is a common invoicing mistake.
If you're registered for GST, you report GST collected and paid on your Business Activity Statement (BAS), typically lodged quarterly. Getting the inclusive/exclusive split right on every invoice line matters: small rounding errors compound across a quarter's worth of transactions. See current BAS due dates for your lodgement deadline.
Adding GST: price excl. GST × 1.1 = price incl. GST.
Removing GST: price incl. GST ÷ 11 = GST component (not ÷10, which overstates the tax by including GST-on-GST).
Net amount: price incl. GST − GST component = price excl. GST.
More worked examples and edge cases are on the FAQ page.
You must give a customer a tax invoice within 28 days of them asking for one, unless the sale is $82.50 (including GST) or less. For taxable sales under $1,000, a valid tax invoice needs to clearly show: that the document is intended to be a tax invoice, your identity and ABN, the issue date, a brief description of the items sold (including quantity and price), the GST amount or a statement that the price includes GST, and the extent to which each item is a taxable sale.
For sales of $1,000 or more, you also need to show the buyer's identity or ABN. A tax invoice built for the $1,000-plus threshold works for smaller sales too, so most businesses just use one invoice format.
Most goods and services carry GST, but some categories are GST-free, meaning no GST is charged but the seller can still claim GST credits on related purchases. Common GST-free categories include most basic food, some medical, health and care services, some education courses and materials, some childcare, exports, and some religious and charitable activities.
Financial supplies, such as loan interest and life insurance, are treated differently again: they're input-taxed rather than GST-free, which means no GST is charged, but GST credits generally can't be claimed on purchases related to making that supply. Full category detail sits with the ATO's GST-free sales guidance; this calculator assumes a standard 10% taxable sale.
For a fast lookup without typing, here's the GST breakdown on typical invoice and quote amounts at the standard 10% rate.
| Amount excl. GST | GST (10%) | Amount incl. GST |
|---|---|---|
| $50.00 | $5.00 | $55.00 |
| $100.00 | $10.00 | $110.00 |
| $150.00 | $15.00 | $165.00 |
| $200.00 | $20.00 | $220.00 |
| $250.00 | $25.00 | $275.00 |
| $500.00 | $50.00 | $550.00 |
| $750.00 | $75.00 | $825.00 |
| $1,000.00 | $100.00 | $1,100.00 |
| $2,000.00 | $200.00 | $2,200.00 |
| $5,000.00 | $500.00 | $5,500.00 |