Sales Tax Calculator
Add your sales-tax rate to a pre-tax price or extract included tax from a total to see price, tax and after-tax amount.
Calculator arithmetic runs locally in your browser and does not require an API.
The interactive calculator loads here when JavaScript is enabled.
How to use Sales Tax Calculator
Choose forward or reverse mode and enter one rate. Confirm whether the whole price is taxable under the rules you are using.
Formula and method
Forward total = price × (1+r). Reverse pre-tax price = total/(1+r). Tax = total − pre-tax price.
Understanding the results
Reverse mode divides by 1+r; subtracting the same percentage of the total would overstate tax. Exemptions, multiple rates and local rounding rules are not modeled.
Worked example
A pre-tax price of 100 at 8.25% adds 8.25 tax for a total of 108.25. Reverse mode at that rate recovers the original 100.
These are mathematical estimates, not financial advice or an offer of credit.
Frequently asked questions
Does the tool select my local rate?
No. Supply the applicable rate yourself; no location lookup is performed.
Can I subtract 8.25% from a tax-inclusive total?
No. Divide the total by 1.0825 to recover its pre-tax price at that rate.
Can this calculate income tax?
No. Sales tax applies to a purchase price; progressive income tax uses income bands and separate rules.