Free sales tax calculator
Enter a price and your local tax rate to find the tax amount and total cost. The optional discount field applies the markdown before tax, just like stores do.
Tax amount
$—
Total (with tax)
$—
Effective tax rate
—%
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How to use
- Enter the pre-tax price of the item or service.
- Enter your local tax rate (combined state + county + city).
- Optionally enter a discount % if the item is on sale.
- The tax amount, final total, and effective rate appear instantly.
Formula
- Tax = price × (rate ÷ 100)
- Total = price + tax
When a discount is applied, the markdown comes off first, then tax is applied to the smaller amount:
- Discounted price = price × (1 − discount% ÷ 100)
- Tax = discounted price × (rate ÷ 100)
- Total = discounted price + tax
Worked examples
$100 item at 8% tax, 20% off
- After discount: 100 × 0.80 = $80
- Tax: 80 × 0.08 = $6.40
- Total: 80 + 6.40 = $86.40
Reverse — finding price from a $108 receipt at 8% tax
- Pre-tax = 108 ÷ 1.08 = $100
- Tax paid = 108 − 100 = $8
Notes
- Combined rates — most states have state + county + city layers. Look up your address on your state revenue website and enter the combined rate as one number.
- Discount before tax is the standard U.S. retail convention, and what this calculator follows. A small number of states (and most of Europe’s VAT) apply tax to the sticker price — those rules aren’t captured here.
- Exemptions — several states exempt groceries, clothing, or prescription drugs. This calculator treats every dollar as taxable; strip the exempt portion from the price before you enter it.
References
- State and Local Sales Tax Rates, 2026Tax Foundation · taxfoundation.org
- Sales TaxWikipedia · en.wikipedia.org
Frequently asked
How is sales tax calculated?
Tax = price × (rate ÷ 100). The total is price + tax. If a discount applies, the discount reduces the price first, then tax is applied to the discounted amount.
What is the effective tax rate?
When a discount is applied, the effective tax rate is the tax as a percentage of the original undiscounted price — always less than the nominal rate.
Does this include local and state tax?
The calculator takes whatever combined rate you enter. Look up your state + city + county combined rate on your state's revenue website and enter it as one number.
How do I reverse-calculate price from total?
Pre-tax price = total ÷ (1 + rate/100). For example, if the total is $108 at 8% tax: 108 ÷ 1.08 = $100.
How do I share my calculation?
Click "Share with my numbers" to copy a URL that restores your price and rate.
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