Calculators & Converters
GST / Sales Tax Calculator
The GST / Sales Tax Calculator adds a tax percentage onto a price to show the total you'll pay, or works the other way around by taking a tax-inclusive total and breaking out the original pre-tax price and the tax amount within it. It suits shoppers checking receipts, freelancers and small business owners quoting prices, and anyone who needs to quickly separate a price from its tax component.
Because the calculation runs entirely client-side, results update instantly as you type an amount or tax rate, with no server call or data upload involved. That makes it convenient for repeated quick checks, whether you're pricing an invoice or double-checking a till receipt.
How to Use the GST / Sales Tax Calculator
- Open the GST / Sales Tax Calculator tool.
- Enter the price amount and the applicable tax rate.
- Choose whether you're adding tax to a pre-tax price or extracting tax from a tax-inclusive total.
- View the calculated tax amount and final total, updated instantly as you adjust inputs.
Frequently Asked Questions
How is tax removed from a tax-inclusive price?
To extract tax from an inclusive total the calculator divides the total by (1 + tax rate) to find the pre-tax price, then subtracts that from the total to find the tax amount.
Does this work for VAT, GST and general sales tax?
Yes, since the underlying maths for adding or extracting a percentage-based tax is the same regardless of what the tax is called in your country, you just enter the applicable rate.
Will this calculate the exact tax rate for my region?
No, the tool does not know local tax rates or rules, so you need to enter the correct percentage yourself and confirm it against official guidance for your jurisdiction.