A sales tax calculator ends the familiar checkout surprise: the shelf price says $49.99, but the register says $54.12. In the US, listed prices generally exclude sales tax because rates differ by state, county, and city — one price tag can't cover them all. This tool adds the tax for you, works the problem backwards when the price already includes tax, and supports multiple items via the quantity field. Everything runs in your browser; nothing is uploaded or stored.
US sales tax rates typically range from 0% to about 10% once state and local taxes combine. Five states have no statewide sales tax — Alaska, Delaware, Montana, New Hampshire, and Oregon (the "NOMAD" states) — though some Alaskan municipalities levy their own. At the high end, places like parts of California, Tennessee, and Louisiana can push combined rates past 9.5%. City and county add-ons explain why two stores an hour apart can charge different tax on the same item.
Two directions cover every use case. Add tax takes a pre-tax price and shows the tax amount plus the final total — the standard "what will this actually cost me?" question. Back out reverses a tax-included price into its before-tax price and the tax embedded in it — handy for business travelers and freelancers expensing purchases, or when comparing US prices to tax-included prices abroad.
How to use the Sales Tax Calculator
- Pick a mode — "Add tax to price" for pre-tax prices, "Back tax out of total" for tax-included ones.
- Enter the price — the number on the tag or receipt, before or after tax depending on the mode.
- Set the tax rate with a state preset or the slider (0–15%).
- Adjust quantity if you're buying more than one of the same item.
- Click Calculate to see the tax amount, the before-tax price, and the final total.
Smart shopper tips
- City and county taxes stack on top of the state rate — check your actual combined rate on the state revenue site, not just the state headline number.
- Food, clothing, and digital goods are often taxed differently from general merchandise in the same state.
- Buying from an out-of-state online seller? Most states now require marketplace sellers to collect the buyer's local rate.
- Freelancers and resellers in many states can claim a resale exemption certificate — no point paying sales tax on inventory you'll resell.
Why US prices hide the tax (and most of the world doesn't)
The US taxes consumption at the point of sale with thousands of overlapping jurisdictions, so publishers of price tags would need a different label for nearly every zip code — retailers simply print the pre-tax price and let the register do the math. Most of the world instead uses VAT baked into the displayed price. Neither system is more honest; they just hide the math in different places. Either way, the number that matters is the final total — which this calculator puts in front of you before you reach the till.
Frequently asked questions
How do I calculate sales tax on a price?
Multiply the pre-tax price by the tax rate as a decimal and add the result to the price. For example, a $100 item with 8% tax costs $108: $100 × 0.08 = $8 tax, then $100 + $8 = $108.
How do I remove sales tax from a total price?
Divide the tax-included price by 1 plus the tax rate as a decimal. A $108 total at 8% tax gives $108 ÷ 1.08 = $100 before tax, so $8 of the total was tax.
Which US states have no sales tax?
Five states have no statewide sales tax: Alaska, Delaware, Montana, New Hampshire, and Oregon (often remembered as NOMAD). Some Alaskan cities and boroughs still levy local sales taxes.
Why does the register total differ from the shelf price?
In the US, listed prices generally exclude sales tax because rates vary by state, county, and city — a shelf price can't cover them all. The tax is added at checkout. Many other countries show tax-included prices, which is why the calculator has a reverse-tax mode.
All calculations are estimates for personal use. Sales tax rules vary by jurisdiction; this tool is not tax advice.