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GST Calculator
Add or remove GST from any amount
About the GST Calculator
The GST Calculator adds or removes Goods and Services Tax from any amount, with quick-select rates of 5%, 12%, 18% and 28%, plus a custom rate field for any other percentage. It's useful for invoicing, checking a receipt, or working out the pre-tax price of an item.
How to Calculate GST
- Choose Add GST or Remove GST.
- Enter the amount.
- Select a GST rate, or enter a custom one.
- Click Calculate GST to see the breakdown.
Key Features
- Add or remove GST in one tool
- Quick-select common GST rates
- Custom rate support for any percentage
- Clear breakdown of base amount, tax and total
FAQ
What does "Remove GST" do?
It works backward from a tax-inclusive total to show you the original pre-tax amount and the tax portion.
Can I use a custom tax rate?
Yes, enter any percentage into the custom rate field instead of using the presets.
Does this work for other sales taxes, not just GST?
Yes, the same math applies to VAT or any other percentage-based sales tax.
Is my data stored anywhere?
No, all calculations happen entirely in your browser.