Sales tax--
Final / pre-tax price--
Sales Tax Calculator
Use this sales tax calculator to estimate purchase totals or reverse-calculate the pre-tax amount from a receipt total.
Updated May 2026No signup requiredBuilt for mobile
Calculator
How to use this calculator
- Enter your values in the calculator fields.
- Check that the units and percent formats match what the label asks for.
- Click Calculate to update the result.
- Use Reset Calculator to restore the starting example.
Formula or calculation method
Sales tax amount = pre-tax amount x tax rate / 100.
Final price = pre-tax amount + sales tax.
Reverse pre-tax amount = final price / (1 + tax rate / 100).
Worked example
A $120 purchase at 8.25% sales tax has $9.90 in tax and a final price of $129.90.
Practical planning tips
- Shopping totals
- Receipt checks
- Vehicle tax estimates
- Budgeting
- Reverse tax math
Common mistakes to avoid
- Entering 0.0825 instead of 8.25 for the tax rate
- Applying tax to items that are exempt
- Forgetting local tax add-ons
FAQ
Sales Tax Calculator questions
Is this calculator exact?
It is a practical estimate based on the values you enter. Verify important decisions with the official source, lender, school, product label, or professional guidance when needed.
Why did I get an error?
The calculator checks for blank fields, invalid numbers, impossible negative values, and divide-by-zero situations. Review the message and adjust the input.
Can I use this calculator on my phone?
Yes. The inputs, buttons, and result cards are built to work on mobile screens.
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