Sales Tax Calculator

Use the free sales tax calculator below to find the tax and total on any purchase in seconds. Enter the amount and your local sales tax rate, and the result updates instantly. Because rates differ by state, county, and city, this one tool replaces a separate page for every rate — just type the rate that applies to you.

What Is Sales Tax?

Sales tax is a consumption tax that state and local governments charge on the sale of most goods and some services. The seller adds it at checkout, collects it from the buyer, and passes it on to the tax authority. It helps fund public services such as schools, roads, and emergency response. The rate you pay is set by your state and often topped up by county and city taxes, which is why the total can vary even within the same state. Most everyday retail purchases are taxable, while items like groceries and prescription medicine are frequently taxed at a reduced rate or exempt entirely.

How to Calculate Sales Tax

Sales tax is a percentage added to the price of a taxable purchase. To work it out by hand, multiply the purchase amount by the tax rate written as a decimal, then add the result to the original price.

1. Convert the rate to a decimal — divide the percentage by 100 (7.25% becomes 0.0725).
2. Multiply the purchase amount by that decimal to get the tax ($100 × 0.0725 = $7.25).
3. Add the tax to the purchase amount for the total ($100 + $7.25 = $107.25).

For example, a $240 purchase in a area with an 8.25% combined rate works out to $240 × 0.0825 = $19.80 in tax, for a $259.80 total. The calculator above does this instantly for any amount and rate.

The Sales Tax Formula

Sales tax = price × (rate ÷ 100), and total = price + sales tax. That’s the entire calculation. The only variable that changes is the rate, which depends on where the sale takes place.

How to Calculate Sales Tax Backwards

Sometimes you have the final total and want to find the original pre-tax price — for example, when separating tax out of a receipt. Divide the total by 1 plus the rate as a decimal: pre-tax price = total ÷ (1 + rate ÷ 100). If a receipt shows $107.25 at a 7.25% rate, the pre-tax price is $107.25 ÷ 1.0725 = $100.00, and the tax portion is $7.25. This is handy for bookkeeping, expense reports, and reconciling cash drawers.

Origin-Based vs. Destination-Based Sales Tax

States collect sales tax in one of two ways. In destination-based states — the majority — the rate is set by where the buyer takes possession of the item, such as their shipping address. In origin-based states, the rate is set by the seller’s location. This distinction matters most for businesses that ship across city or county lines, because the combined local rate can change from one ZIP code to the next.

Do You Pay Sales Tax on Online Purchases?

Usually, yes. Since the 2018 South Dakota v. Wayfair Supreme Court decision, states can require online retailers to collect sales tax once they pass a sales threshold in that state, even without a physical store there. In practice, most online orders are taxed based on the delivery address. If a retailer doesn’t charge it, you may still owe the equivalent “use tax” directly to your state.

Sales Tax vs. Use Tax

Sales tax and use tax are two sides of the same coin. Sales tax is collected by the seller at checkout. Use tax applies when you buy something taxable without paying sales tax — for instance, from an out-of-state seller that didn’t collect it — and you’re expected to report and pay it yourself, often on your state income-tax return. The rate is generally the same as the sales tax rate for your location.

Which States Have No Sales Tax?

Five states have no statewide sales tax, easy to remember by the acronym NOMAD: New Hampshire, Oregon, Montana, Alaska, and Delaware. Note that some local jurisdictions in Alaska still add their own sales tax, so “no state tax” doesn’t always mean “no tax at all.” Everywhere else, you’ll pay a combined state-and-local rate that the calculator above can apply for you.

Tips for Getting the Rate Right

• Look up the combined rate (state + county + city), not just the state rate.
• For shipped or online orders, use the delivery address in destination-based states.
• Check your state department of revenue site, which publishes rates by address or ZIP code.
• Remember that some items — groceries, prescription drugs, clothing in certain states — are taxed at a lower rate or exempt entirely.

Frequently Asked Questions

How do I calculate sales tax? Multiply the price by the tax rate written as a decimal, then add it to the price. For example, $50 at 8% is $50 × 0.08 = $4 tax, for a $54 total.

How do I figure out the tax from a total? Divide the total by 1 plus the rate as a decimal. At 7%, a $53.50 total is $53.50 ÷ 1.07 = $50.00 before tax.

Which states have no sales tax? New Hampshire, Oregon, Montana, Alaska, and Delaware have no statewide sales tax. Local sales taxes may still apply in parts of Alaska.

Is sales tax based on where I buy or where I live? For most in-store purchases it’s based on where the sale happens. For online and shipped orders it’s usually based on the delivery address. Rules vary by state.

Do I pay sales tax on online orders? In most cases, yes — retailers typically collect it based on your shipping address. If they don’t, you may owe use tax directly to your state.

How do I find my local sales tax rate? Check your state department of revenue website, which lists combined state-and-local rates by address or ZIP code.

Is Sales Tax Charged on Shipping?

It depends on the state. Some states tax shipping and handling charges when the item being shipped is taxable, while others exempt shipping as long as it’s listed separately on the invoice. When shipping is bundled into the item price rather than stated on its own line, it’s more likely to be taxed. This is a common source of small errors on invoices and receipts, so if you sell or ship goods, check your state’s specific rule and apply it consistently. The calculator above works on whatever taxable amount you enter, so include shipping in the amount only if your state taxes it.

This calculator and the information here are provided for general informational purposes only and are not tax or legal advice. Confirm current rates and rules with your state or local tax authority.

Official resource: for the rules that apply to your situation, see the IRS.