BAS Calculator Australia 2026
Estimate your quarterly GST amounts for your Business Activity Statement. Enter your sales and purchase figures to calculate GST payable or refund.
BAS Details
GST Summary
BAS Label Summary
These correspond to the labels on your official BAS form.
| Label | Description | Amount |
|---|---|---|
| G1 | Total Sales (including GST) | $50,000.00 |
| G2 | Export Sales | $0.00 |
| G3 | Other GST-free Sales | $5,000.00 |
| G9 | Taxable Sales | $45,000.00 |
| 1A | GST on Sales | $4,090.91 |
| G10 | Capital Purchases | $0.00 |
| G11 | Non-capital Purchases | $30,000.00 |
| 1B | GST on Purchases | $2,727.27 |
| 1C | GST Payable | $1,363.64 |
What is a BAS (Business Activity Statement)?
A Business Activity Statement (BAS) is a tax reporting requirement for all Australian businesses registered for GST. It is submitted to the Australian Taxation Office (ATO) either monthly, quarterly, or annually depending on your business size and reporting obligations. The BAS is used to report and pay goods and services tax (GST), pay-as-you-go (PAYG) instalments, PAYG withholding, and other tax obligations.
Quarterly BAS lodgement dates in Australia are: Q1 (July-September) due 28 October, Q2 (October-December) due 28 February, Q3 (January-March) due 28 April, and Q4 (April-June) due 28 July. Late lodgement can result in penalties from the ATO, so it is important to lodge on time.
GST in Australia is calculated at a flat rate of 10%. If your prices include GST, you divide by 11 to find the GST component. For example, a sale of $1,100 (incl. GST) contains $100 GST. Your net GST obligation is GST on Sales - GST on Purchases = GST payable (or refund). All calculations in this tool run entirely in your browser with no data sent to any server.
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Frequently Asked Questions
What is a BAS (Business Activity Statement)?
A Business Activity Statement (BAS) is a form submitted to the Australian Taxation Office (ATO) by registered businesses to report and pay their tax obligations, including GST, PAYG instalments, PAYG withholding, and other taxes. Most small businesses lodge their BAS quarterly.
When are quarterly BAS due dates in Australia?
Quarterly BAS due dates are: Q1 (July-September) due 28 October, Q2 (October-December) due 28 February, Q3 (January-March) due 28 April, and Q4 (April-June) due 28 July. If you lodge through a registered tax agent, you may get an extension.
How is GST calculated on the BAS?
GST in Australia is 10%. If your prices include GST, divide the GST-inclusive amount by 11 to find the GST component. For example, if total sales are $110,000 (including GST), the GST amount is $110,000 / 11 = $10,000. You then subtract the GST on your purchases to determine your net GST payable or refund.
What is the difference between cash and accrual BAS reporting?
Cash basis means you report GST in the period you receive or make payment. Accrual basis means you report GST in the period you issue or receive an invoice, regardless of when payment occurs. Businesses with turnover under $10 million can choose either method. Cash basis is simpler for most small businesses.