GST Calculator Australia — Add or Remove 10% GST
Calculate GST on any amount instantly. Add 10% GST to a price or remove GST from an inclusive amount. Use the BAS helper to prepare your quarterly Business Activity Statement. Check if your business needs to register for GST.
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How to Use This Calculator
Add/Remove GST tab
Enter an amount and select whether to add GST (calculate GST-inclusive price from an ex-GST amount) or remove GST (extract the GST component from an inclusive price). The calculator shows the GST amount, both prices, and the 1/11 fraction.
BAS Helper tab
Enter your total sales (GST-inclusive), total purchases (GST-inclusive), and export sales for the quarter. The calculator computes GST collected, GST credits, and the net amount payable to the ATO or refundable to you.
Registration Check tab
Enter your annual turnover and business type. The calculator tells you whether GST registration is required, what threshold applies, and when your next BAS is due.
Share your result
All inputs are encoded in the URL. Click Share to send your exact calculation to a client, accountant, or colleague.
The Formula
GST = Price × 10%
GST-inclusive price = Price × 1.10
Remove GST (from inclusive price):
GST = Price ÷ 11 (Division 11 method)
GST-exclusive price = Price ÷ 1.10
BAS Calculation:
GST collected = Total sales (incl.) ÷ 11
GST credits = Total purchases (incl.) ÷ 11
Net GST = GST collected − GST credits
Positive = pay to ATO. Negative = refund.
Registration Threshold:
For-profit: $75,000 annual turnover
Non-profit: $150,000 annual turnover
Taxi/ride-share: Mandatory (any turnover)
Worked Example
Small business quarterly BAS
A sole trader with quarterly sales of $55,000 (GST-inclusive) and purchases of $33,000 (GST-inclusive).
Step 1: Calculate GST on an invoice
Step 2: Quarterly BAS
Verdict: The business owes $2,000 to the ATO for this quarter. The business collected $5,000 in GST from customers and paid $3,000 in GST on purchases. The $2,000 difference is remitted to the ATO by the BAS due date.
GST Quick Reference
GST rate and thresholds
| Parameter | Value |
|---|---|
| GST rate | 10% |
| Registration threshold (for-profit) | $75,000 |
| Registration threshold (non-profit) | $150,000 |
| Taxi/ride-share | Mandatory |
| BAS lodgement | Quarterly (monthly if >$20M) |
BAS due dates
| Quarter | Period | Due Date |
|---|---|---|
| Q1 | July – September | 28 October |
| Q2 | October – December | 28 February |
| Q3 | January – March | 28 April |
| Q4 | April – June | 28 July |
Electronic lodgers may get an extra 2 weeks. Check ATO for specific due dates if they fall on a weekend or public holiday.
GST-free items
| Category | Examples |
|---|---|
| Basic food | Bread, milk, fruit, vegetables, meat, eggs (not restaurant meals or takeaway) |
| Health | Medical services, prescription medicines, private health insurance |
| Education | Tuition fees, course materials at registered institutions |
| Exports | Goods and services exported from Australia |
| Water & sewerage | Water supply and sewerage services |
| Childcare | Registered childcare and early learning services |
GST-free means no GST is charged, but the supplier can still claim GST credits on inputs. Different from input-taxed supplies (e.g., residential rent, financial supplies) where no GST credits can be claimed.