How it works
Sales tax is a percentage levied by state and local governments on most retail purchases, added at the register on top of the listed price. This calculator works both directions. Forward, it adds a combined state-and-local rate to a pre-tax price to produce the checkout total. Backward, it strips the tax out of a tax-inclusive amount to recover the pre-tax price and the tax hidden inside it — and the extraction is division, not subtraction: dividing by one-plus-the-rate is what recovers the true base, while subtracting the percentage always leaves too much behind. There is no federal sales tax in the United States: statewide rates run from zero in Alaska, Delaware, Montana, New Hampshire and Oregon to 7.25% in California, before local additions push combined rates past 9% in some cities. Most states levy tax where the buyer receives the goods — destination-based — and online marketplaces now collect and remit it automatically in most cases, which is why cart totals match the calculator's forward mode.
Formula
Add: total = price x (1 + rate/100) | Remove: pre-tax = total / (1 + rate/100)
Tips
- There is no US federal sales tax — the rate is whatever your state plus locality charges.
- Five states have no statewide sales tax — Alaska, Delaware, Montana, New Hampshire, Oregon — though Alaska's locals add their own.
- Most states are destination-based: the rate follows the delivery address, not the seller's.
- Removing tax means dividing by (1 + rate), never subtracting the percentage from the total.
- Groceries, prescriptions and clothing are exempt or reduced in many states — sticker rate rarely hits every line.
Frequently asked questions
- How do I add sales tax to a price?
- Multiply the price by (1 + rate). At 8.25%, an $89.99 item becomes $89.99 x 1.0825 = $97.41, of which $7.42 is tax. Use the combined state-plus-local rate for the delivery address to match a real checkout.
- How do I remove sales tax from a total?
- Divide the total by (1 + rate). A $108.25 receipt at 8.25% contains $108.25 / 1.0825 = $100.00 before tax and $8.25 of tax. Subtracting 8.25% from $108.25 gives the wrong answer — division is what back tax out correctly.
- Which states have the highest sales tax?
- California has the highest statewide rate at 7.25%; Tennessee, Louisiana, Arkansas and Washington carry some of the highest combined state-plus-local averages, with certain city combinations exceeding 9-10%. Several New England and Rocky Mountain states sit near zero.
- Why do some states have no sales tax?
- Alaska, Delaware, Montana, New Hampshire and Oregon raise revenue through other channels — income, property or resource taxes — and lean on sales-tax-free status as a retail draw. Local option taxes still exist, notably in Alaska, so the checkout rate is not always zero.
- Do online purchases include sales tax?
- Yes in nearly all cases since the South Dakota v. Wayfair decision and marketplace facilitator laws: large platforms collect and remit tax on your behalf at the destination rate. Small out-of-state sellers without nexus remain the rare exception, technically leaving use tax self-reporting to the buyer.