Sales Tax Calculator
Calculate sales tax amount and total price with tax. Also reverse-calculate the pre-tax price from a tax-inclusive total. Works for any state or local rate.
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Sales Tax Amount
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Total Price (with tax) —
Pre-tax Price (if total given) —
How to Use This Calculator
- Enter the Pre-tax Price — the item price before tax.
- Enter the Sales Tax Rate — look up your state + local combined rate.
- See the Tax Amount and Total Price instantly.
- The Pre-tax from Total field shows how to reverse-calculate the pre-tax price from a tax-inclusive total.
Formula
Tax Amount = Price × Tax Rate ÷ 100
Total Price = Price + Tax Amount
Pre-tax from Total = Total ÷ (1 + Tax Rate ÷ 100)
Example
Example: $100 purchase, 8.5% sales tax.
- Tax Amount: $100 × 8.5% = $8.50
- Total Price: $108.50
- If given total $108.50: Pre-tax = $108.50 ÷ 1.085 = $100.00
Frequently Asked Questions
- The average combined state and local sales tax rate in the US is about 7.0–8.5%. California (10.25% average combined), Tennessee (9.55%), and Arkansas (9.47%) have the highest average rates. Oregon, Montana, Delaware, and New Hampshire have no sales tax.
- Multiply the pre-tax price by the tax rate as a decimal. For 8.5% tax on $100: $100 × 0.085 = $8.50 tax. Total = $100 + $8.50 = $108.50. For mental math: 8% of $100 = $8, plus 0.5% ($0.50) = $8.50.
- Divide the total by (1 + tax rate). If the total is $108.50 and tax rate is 8.5%: $108.50 ÷ 1.085 = $100 pre-tax price. Do NOT subtract the tax rate percentage from the total directly.
- No — many states exempt groceries, prescription drugs, and clothing from sales tax. The rules vary by state and product category. Some states tax services; others do not. Check your state's revenue department for specifics.
- Yes, since the 2018 South Dakota v. Wayfair Supreme Court decision, states can require online retailers to collect sales tax regardless of physical presence. Most major online retailers now collect the appropriate state/local sales tax.