Buy the same laptop in Portland, Oregon and in New Orleans, Louisiana and the amount you hand over differs by roughly a tenth of the price. Nothing about the laptop changed. What changed is that sales tax in the United States is not one tax — it is thousands of overlapping taxes set by independent governments.
There is no national sales tax
The federal government does not levy a general sales tax. Most countries that tax consumption do so with a single national value-added tax at a uniform rate, collected at every stage of production and displayed in the shelf price.
The US does the opposite. States set their own rates, and most states then authorize counties, cities, and special districts — transit authorities, stadium districts, school districts — to layer their own rates on top. The result is a patchwork with thousands of distinct combined rates, which is why the number at the register can change when you cross a street.
The five states without one — and the asterisk
Alaska, Delaware, Montana, New Hampshire, and Oregon have no statewide sales tax. In four of them, most retail purchases carry no sales tax at all.
Alaska is the exception worth knowing. It has no state rate but allows municipalities to impose their own, so residents of some Alaskan boroughs pay meaningful local sales tax while others pay none. The population-weighted average combined rate in Alaska works out to roughly 1.82%.
It is also worth resisting the conclusion that no sales tax means low taxes overall. States fund themselves somehow. New Hampshire has no sales tax and no wage income tax, and correspondingly high property taxes. Oregon has no sales tax and a relatively high income tax. The mix moves; the total does not vanish.
Where the rates actually land
On a population-weighted average of combined state and local rates, the highest are Louisiana at about 10.13%, Tennessee at 9.61%, Washington at 9.57%, Arkansas at 9.48%, and Alabama at 9.46%.
Averages hide the spread inside a state. A state can have a modest statewide rate and very high local add-ons, which is exactly Louisiana's pattern: a 5% state rate with local rates pushing the average past ten. Colorado is similar — a 2.9% state rate, one of the lowest in the country, with combined rates averaging near 7.89% once local jurisdictions are counted.
This is why a state-level rate is nearly useless for budgeting an actual purchase. What you need is the combined rate at the delivery address.
Why the same store taxes two items differently
On top of rate variation, states decide independently what is taxable at all. Most exempt unprepared groceries entirely or apply a reduced rate. Nearly all exempt prescription drugs. A small number exempt clothing.
The boundaries produce genuinely strange statutory language, because someone has to define where groceries end and prepared food begins. Several states draw a distinction between candy and other sweets based on whether the product contains flour, with the practical result that two similar items on adjacent shelves face different rates.
Many states also run temporary sales tax holidays — usually a weekend before the school year when clothing and school supplies below a price cap are exempt.
Online purchases and the Wayfair rule
Until 2018, a state generally could not require a retailer to collect its sales tax unless the retailer had a physical presence there. That is why early online shopping often arrived untaxed.
In South Dakota v. Wayfair, the Supreme Court overturned the physical-presence requirement, allowing states to impose collection duties based on economic activity — typically a threshold of annual sales or transaction count in that state. Essentially every state with a sales tax adopted such a rule, and large online retailers now collect nearly everywhere.
Where a seller does not collect, most states impose a corresponding use tax that the buyer owes directly at the same rate. It is rarely enforced against individuals for small purchases, but it exists, and it applies to things like a car bought out of state and registered at home.
What this means practically
For everyday budgeting, use your local combined rate, not your state rate — the difference is often two or three percentage points. For a large purchase, the rate at the delivery or registration address is what governs, which occasionally makes where you take delivery a real decision.
And when comparing states as places to live, sales tax is one line in a longer list that includes income tax, property tax, and what the state actually funds. Comparing any one of them alone reliably produces the wrong conclusion.