Free tool

GST calculator for Australia

Free Australian GST calculator. Type in an amount and tell it whether GST is already included, and it shows the GST component, the ex-GST figure and the inc-GST total. Switch modes to estimate how much GST you owe for the quarter from your total sales and purchases, laid out the way your BAS asks for it.

What do you want to work out?

Amount

Any price, invoice total or receipt amount.

This amount

GST is 1/11 of a GST-inclusive amount.

GST component
$100.00
1/11 of the amount
Amount excluding GST
$1,000.00
GST (10%)
$100.00
Amount including GST
$1,100.00
Australian GST is a flat 10%. To remove it from a GST-inclusive price, divide by 11. To add it to a GST-exclusive price, multiply by 0.1. Some items are GST-free (basic food, most health and education, exports) or input taxed (residential rent, most financial supplies), so not every amount on a receipt carries GST.

Email me these results

The numbers above, then a few short emails on getting your BAS done. Unsubscribe any time.

How it works

  • GST in Australia is 10%. If a price excludes GST, add 10%. If a price already includes GST, the GST inside it is one eleventh of the total, not 10%, because the 10% was added to a smaller base.
  • On your BAS, 1A is the GST you collected on sales and 1B is the GST you paid on business purchases. Each is 1/11 of the GST-inclusive totals if everything carried GST.
  • Net GST is 1A minus 1B. Positive means you pay the ATO with your BAS; negative means the ATO refunds you. FlowFi works these labels out from your bank statement each quarter.

Embed this tool on your site

Paste this code into any page of your website, blog or client portal and the tool appears there, kept up to date by us. It works on WordPress, Squarespace, Wix, Webflow and anything else that accepts HTML.

<iframe src="https://flowfi.com.au/embed/gst-calculator" width="100%" height="520" style="border:0" title="Australian GST calculator, by FlowFi"></iframe>

Free to embed, please keep the Powered by FlowFi link.

Related guide
How to calculate GST in Australia

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