About Australian GST Calculator

Who publishes this site

This site is a Shmarlo project. Shmarlo is a Melbourne-based digital business run by Carlo Santoro, which builds and operates online tools and platforms.

You can reach us through the contact page.

What you will find here

A calculator that adds GST to a price or removes it from a GST-inclusive price and shows the workings, a library of guides on GST registration, tax invoices, credits, the Business Activity Statement and related topics, and a glossary of more than 370 tax and GST terms, each with its own page and a link to the official ATO guidance.

How the content is written

The guides and glossary are drafted with the help of AI tools and written to follow the ATO’s public guidance. Wherever a figure changes from year to year, such as tax brackets, super rates and thresholds, we tell you to check the ATO instead of printing a number that may be out of date. Every guide and glossary page links to a relevant ATO page so you can confirm the detail at the source.

This content has not been independently reviewed by a registered tax practitioner. It is general information, not advice. The content was last reviewed on 25 October 2026.

Not affiliated with the ATO

This site is independent. It is not run by, endorsed by or affiliated with the Australian Taxation Office or any government body. It does not provide tax advice or tax agent services. For advice on your own situation, speak to the ATO or a registered tax or BAS agent.

Corrections

Tax rules change and mistakes happen. If you spot something wrong or out of date, please tell us through the contact page and include the page address. We correct confirmed errors and update the review date on the page.

How the site is funded

The site is free to use. It shows advertising served by Google AdSense, which pays for hosting and development. Ads are labelled and do not change what the guides say. See the privacy policy for how advertising uses cookies.