BAS Estimator Australia
Quarterly BAS due and not sure what you owe? Drop in your sales, purchases and any PAYG withholding, and we'll estimate your GST collected, GST credits, net GST, and the bottom line you'll pay or get back.
- GST collected on sales (1A)$0
- GST credits on purchases (1B)$0
- Net GST$0
- PAYG withholding (W2)$0
- PAYG instalment$0
Enter your sales and purchases to see your estimate.
Want it lodged on time, every time, with the numbers checked? We do that.
Get BAS lodged for you →General information only, current for the 2025-26 financial year. This is a quick GST estimate for a business registered on a cash or accruals basis at the standard 10% rate. It ignores capital purchases, fuel tax credits, wine equalisation and luxury car tax, adjustments, and any rounding the ATO applies, and is not personal tax advice. For a BAS you can lodge with confidence, talk to us.
A Few Things This Calculator Assumes
How is GST worked out from a GST-inclusive figure?
When a price already includes 10% GST, the GST portion is one eleventh (1/11) of that price, not 10%. So on $1,100 of GST-inclusive sales the GST is $100. We apply 1/11 to your taxable sales for GST collected, and 1/11 to your purchases that carry GST for your GST credits.
What is net GST, and when do I get a refund?
Net GST is the GST you collected on sales minus the GST credits on your purchases. If you collected more than you spent, you pay the difference. If your credits are larger (common when you've made big purchases or had a quiet quarter), the net GST is a refund and shows as a negative figure.
How does PAYG withholding change the total?
If you have employees, the tax you withhold from their wages (W2 on the BAS) is reported and paid on the same form. We add it to your net GST, along with any PAYG income tax instalment, to give the total amount payable to the ATO. PAYG amounts are always payable, so they reduce a refund or increase what you owe.
Cash basis or accruals, which figures do I use?
On a cash basis you use sales you've actually been paid for and purchases you've actually paid. On an accruals basis you use invoices issued and received, paid or not. This estimator works for either, as long as the totals you enter match your method. We set this up correctly when we manage your bookkeeping and BAS.
BAS Due Soon? Hand It Over
Book a quick call and we'll take the quarterly BAS off your plate, check the GST is right, and lodge it on time so you're never chasing a deadline or an ATO penalty.
Free · No lock-in · 2-hour reply guarantee