Walk into a store in one city and a $100 jacket rings up at $106. Drive twenty minutes to the next town and the same jacket costs $109. Cross a state line and it might cost exactly $100. That gap is sales tax, and in the United States it isn't one number set in Washington, it's a patchwork of state and local rates that changes block by block. Understanding how those layers stack is the difference between budgeting accurately and being surprised at the register.
This guide explains how US sales tax actually works in 2025: how a state base rate combines with local add-ons to form the combined rate you really pay, which states charge no sales tax at all, where rates climb the highest, and which everyday purchases are commonly exempt. We finish with a fully worked dollar example so you can run the math yourself.
This article is for general informational and educational purposes only and is not professional tax advice. Sales tax rules and rates change frequently and vary by location, so confirm your local rate before relying on these figures.
How US Sales Tax Works: State Base + Local Add-Ons
Unlike income tax, there is no federal sales tax in the United States. Instead, sales tax is set at the state level, and then most states let counties, cities, and special districts (transit authorities, stadium districts, and the like) tack on their own additional rates. Your final, all-in rate is the combined sales tax rate, and it's the only number that matters at checkout:
- State base rate — the statewide rate the legislature sets. This applies almost everywhere in the state.
- Local add-on rates — extra percentages layered on by your county, city, and any special taxing districts.
- Combined rate — the state base plus every local add-on, summed together. This is what you're charged.
The formula is simply: State base rate + Local add-ons = Combined rate. Because local pieces vary, two addresses in the same state can have meaningfully different combined rates. A purchase in a downtown business-improvement district might carry a higher rate than one in a rural county a few miles away. This is why a clean rule of thumb like "my state's tax is 6%" is usually wrong, your combined rate is what hits your wallet, and it's often a full point or two higher than the state base alone. Our Sales Tax Calculator lets you plug in any combined rate to see the tax and total instantly.
The States With No Sales Tax
Five states impose no statewide sales tax in 2025. A handy mnemonic is NOMAD: New Hampshire, Oregon, Montana, Alaska, and Delaware. But there's an important asterisk on Alaska:
- Delaware — no state and no local sales tax. (It does levy a gross receipts tax on businesses, but that's not charged to shoppers at the register.)
- Montana — no general statewide sales tax, though a handful of tourist resort towns levy small local resort taxes.
- New Hampshire — no general sales tax (it does tax prepared meals, lodging, and car rentals).
- Oregon — no state or local general sales tax.
- Alaska — no statewide sales tax, but local sales taxes are allowed. Many Alaskan boroughs and cities charge their own local rate, so depending on where you shop you may still pay sales tax even though the state rate is zero.
So if you want a true zero at every register, the cleanest options are Delaware, Montana, New Hampshire, and Oregon. In Alaska, your bill depends entirely on the local jurisdiction, the state simply stays out of it.
Where Combined Rates Climb the Highest
At the other end of the spectrum, the layering of local add-ons pushes combined rates well into double digits in some areas. A few patterns are worth knowing in 2025:
- Louisiana has one of the highest average combined rates in the country, often near or above 10%, driven by aggressive local add-ons on top of a raised state rate.
- Tennessee, Arkansas, Washington, and Alabama also routinely post average combined rates in the 9% to 9.5% range.
- California has the highest state base rate at 7.25%, and with local add-ons many cities exceed 10%.
- Specific localities can run even higher, some cities top 10.5% or more once city and special-district taxes pile on.
The takeaway: the state with the highest base rate isn't always the state where you pay the most, because local add-ons do so much of the heavy lifting. A state with a modest base rate but generous local taxing authority can easily out-tax a state with a higher base rate but few local add-ons. Always check the combined rate for the exact place you're buying.
Common Exemptions: Groceries and Prescriptions
Not everything you buy is taxed the same way. States carve out exemptions for goods they consider necessities, which keeps the tax from being too regressive. The two most widespread exemptions are:
- Groceries. Most states fully exempt unprepared food (the raw ingredients you cook at home) or tax it at a reduced rate. The key distinction is usually prepared versus unprepared food: a bag of rice may be tax-free, while a hot deli sandwich or restaurant meal is fully taxed. A shrinking number of states still tax groceries at the full rate, sometimes with an offsetting credit.
- Prescription medications. Prescription drugs are exempt from sales tax in nearly every state. Over-the-counter medicines are treated less consistently, often taxable unless prescribed.
Other common exemptions or reduced rates include certain medical devices, some clothing (a few states exempt clothing entirely or below a price threshold), and items bought during temporary sales-tax holidays, short windows, often before the school year, when states waive tax on clothing, school supplies, or electronics up to a set price. Because these rules are so state-specific, the safest move is to check your state's tax page (the state Department of Revenue website) for exactly what's exempt where you live.
A Fully Worked Example
Let's run real numbers. Imagine you're buying a $1,200 laptop in a city with a state base rate of 6.0% plus a county add-on of 1.0% and a city add-on of 1.5%.
Step 1: Find the combined rate. Add the layers together:
| Component | Rate |
|---|---|
| State base rate | 6.0% |
| County add-on | 1.0% |
| City add-on | 1.5% |
| Combined rate | 8.5% |
Step 2: Calculate the sales tax. Multiply the price by the combined rate:
- $1,200 × 8.5% = $102.00 in sales tax
Step 3: Find the total. Add the tax to the price:
- $1,200 + $102 = $1,302.00 total
Now watch how the location changes everything. Buy that exact same laptop in Oregon, where there's no sales tax, and you pay a flat $1,200, saving the full $102. Buy it in a high-rate Louisiana parish near 10%, and the tax jumps to about $120, for a $1,320 total. Same laptop, a $120 swing, driven entirely by where you stand. To skip the arithmetic, enter the price and your combined rate into our Sales Tax Calculator and it returns the tax and grand total in one step. It also works in reverse if you have a tax-included total and want to back out the pre-tax price.
Sales Tax vs. Income Tax: The Bigger Picture
It's tempting to chase the lowest sales tax, but smart budgeting looks at the whole tax picture. States that charge no sales tax often make up the revenue elsewhere. Oregon, for instance, has no sales tax but a relatively high state income tax, while states like Tennessee and Washington lean heavily on sales tax precisely because they have no broad income tax. A zero at the register can quietly mean a bigger bite out of your paycheck.
That's why your combined tax burden, sales tax plus income tax plus property tax, is what actually determines how far your money goes. If you're weighing a move or comparing job offers in different states, the sales tax rate is only one input. The far bigger lever for most households is what lands in your bank account each pay period after income tax and payroll deductions. Use our Take-Home Pay Calculator to see your real net pay in a given state, then layer in the sales tax you'll face on everyday spending to get the complete picture. A state with no income tax but a 9.5% sales tax can be a great deal for a high earner who saves aggressively, and a worse one for a family that spends most of what it makes.
Sales Tax and Online Purchases
A common modern question: do you owe sales tax on things you buy online? Since the 2018 South Dakota v. Wayfair Supreme Court decision, the answer is almost always yes. Retailers are now generally required to collect sales tax based on the buyer's shipping address, so an online order is taxed at your local combined rate, not the seller's. That closed the old loophole where shopping online dodged sales tax entirely.
Two practical notes follow from this. First, your delivery address determines the rate, so the same online cart can cost different totals depending on where it ships. Second, if a seller doesn't collect tax (rare now, but possible for very small sellers), many states technically require you to report and pay use tax, the mirror image of sales tax, on your state return. For everyday shoppers this is mostly handled automatically at checkout, but it's why the tax on your online receipt matches your home town's combined rate.
The Bottom Line
US sales tax is a layered system: a state base rate plus local add-ons equals the combined rate you actually pay, and that combined rate can swing from 0% in Delaware, Montana, New Hampshire, and Oregon (with Alaska charging local-only) to over 10% in the highest-rate cities. Necessities like groceries and prescription drugs are commonly exempt, but the details are intensely local, so checking your state's tax page is always the smart final step.
For any specific purchase, drop the price and your combined rate into the Sales Tax Calculator to see the tax and total in seconds. And because sales tax is only one piece of your overall burden, pair it with the Take-Home Pay Calculator to understand how a state's full tax mix, sales, income, and payroll, shapes what you really keep. A minute of math beats a surprise at the register or on April 15.
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