About the Sales Tax Calculator
Add sales tax to a price, or work backwards from a tax-inclusive total to the pre-tax price and tax amount.
Also known as: sales tax, tax on purchase, add tax to price, gst calculator, price with tax.
How to use this calculator
- Enter price, sales tax rate, price is.
- The result updates instantly as you type — press Calculate (or Enter) at any time.
- Review the breakdown shown under the main result.
- Use Copy result or Share to save the answer or send a link with your inputs.
Formula
Tax = price × rate · Total = price × (1 + rate)
Worked example
Using the values pre-filled in the calculator above:
- Price = 100
- Sales tax rate = 8.25 %
- Price is: Before tax
the calculator returns:
- Total with tax: 108.25
- Sales tax: 8.25
- Pre-tax price: 100