This sales tax calculator works in both directions: add sales tax to a pre-tax price to see the checkout total, or start from a receipt total and back out how much of it was tax. Enter the price and your combined state and local tax rate, and the tax amount and final price appear instantly.
Sales tax in the United States is set by states, counties, and cities rather than the federal government, so the rate you actually pay depends on where the sale happens. Combined rates range from 0% in a handful of states to more than 10% in some cities.
How Sales Tax Is Calculated
Adding tax to a price is a straightforward percentage:
- Sales tax = pre-tax price × (rate ÷ 100)
- Total price = pre-tax price + sales tax, or pre-tax price × (1 + rate ÷ 100)
Extracting tax from a tax-included total is the reverse — and the step people most often get wrong. You cannot simply multiply the total by the tax rate, because the total already includes tax. Instead divide:
- Pre-tax price = total ÷ (1 + rate ÷ 100)
- Tax paid = total − pre-tax price
For example, a $107.25 receipt at 7.25% breaks down to $107.25 ÷ 1.0725 = $100.00 pre-tax and $7.25 of tax.
State Sales Tax Rates at a Glance
Base state rates vary widely, and most states let local governments add more on top. Some reference points:
- California: 7.25% state base — the highest in the nation; local additions push some cities past 10%
- Texas: 6.25% state base, up to 8.25% with local taxes
- New York: 4% state base, about 8.875% in New York City
- Florida: 6% state base
- Colorado: 2.9% state base — the lowest of any state that charges sales tax
- No statewide sales tax: Oregon, Delaware, Montana, New Hampshire, and Alaska (though some Alaska localities levy their own)
Many states also exempt or discount groceries and prescription drugs, so the rate can differ by item.
Example: $650 Laptop in Texas
Say you buy a $650 laptop in a Texas city charging the maximum combined rate of 8.25% (6.25% state + 2% local).
- Sales tax: $650 × 0.0825 = $53.63
- Total at checkout: $650 + $53.63 = $703.63
Now the reverse case: your card statement shows $703.63 and you need the pre-tax amount for an expense report. Divide by 1.0825: $703.63 ÷ 1.0825 = $650.00, meaning $53.63 of the charge was tax. Buying the same laptop in Oregon, which has no sales tax, would cost exactly $650 — a $53.63 difference on a single purchase.
Frequently Asked Questions
How do I calculate sales tax on a price?
Multiply the price by the tax rate as a decimal. For a $100 item at 7.25%, the tax is $100 × 0.0725 = $7.25, making the total $107.25. Use your combined state plus local rate, not just the state base rate.
How do I back out sales tax from a total?
Divide the total by 1 plus the rate as a decimal. A $53.49 receipt at 7% breaks down as $53.49 ÷ 1.07 = $49.99 pre-tax, leaving $3.50 as tax. Multiplying the total by the rate instead would overstate the tax.
Which states have no sales tax?
Five states charge no statewide sales tax: Oregon, Delaware, Montana, New Hampshire, and Alaska. Alaska is a partial exception — the state itself charges nothing, but some cities and boroughs levy local sales taxes of up to about 7.5%.
Why is my local sales tax higher than my state’s rate?
Most states allow counties, cities, and special districts to add local sales taxes on top of the state base. New York’s state rate is only 4%, but New York City shoppers pay about 8.875% once city and transit district taxes are included.
Do I pay sales tax on online purchases?
Usually yes. Since the 2018 South Dakota v. Wayfair Supreme Court decision, states can require out-of-state sellers to collect sales tax based on the delivery address. Large retailers now collect it automatically in every state that has a sales tax.