GST, Tax & Business

GST Calculator

Use this free online tool to complete a common task. Enter the requested values, calculate the result, and read the guidance below.

Use the tool

What is the GST Calculator?

Calculate an illustrative Goods and Services Tax amount from a price and GST rate. Confirm the applicable rate and whether the entered price is tax-exclusive or tax-inclusive before using the result for invoicing.

How to use this tool

Read each input label and enter the value in the stated unit.
Check the values carefully, including rates, dates and decimal places.
Select Calculate result and read the result note.
For comparisons, change one value at a time and record the assumptions used.

Formula and important notes

For an exclusive price, GST = taxable value × rate ÷ 100; total = taxable value + GST.

Example and practical tips

Start with a simple example to understand how the inputs affect the output. Use up-to-date rates and measurements, and remember that estimates may not include additional fees, local rules, rounding or special circumstances. Keep a copy of your assumptions when comparing options.

Frequently Asked Questions

What is the GST Calculator used for?

GST Calculator is designed to help with a task related to all tools. Enter the required information and read the result notes to understand what the estimate includes.

How do I use the GST Calculator?

Enter the values requested in the GST Calculator, check units and percentages, then select Calculate. Review the result and change one input at a time if you want to compare scenarios.

Can I rely on the result for official decisions?

Treat the result as a guide, not a guarantee. Verify important financial, tax, health, construction or business figures with the relevant professional, provider or official source.

Is this tool free to use?

Yes. The tool is available without creating an account. Avoid entering passwords, payment credentials or other confidential information.