How do I find the sales tax rate for my address?

Combine the state rate with any county, city and special-district rates that apply at your delivery or point-of-sale address. Many state department-of-revenue websites publish a lookup tool by ZIP code or address, since a single ZIP code can span more than one district rate.

Why did two receipts for the same item show different tax amounts?

The most common causes are different delivery addresses under destination-based tax rules, a category exemption applying to one purchase but not the other, or a rate change that took effect between the two purchase dates.

Is sales tax charged on the price after a discount or before it?

Generally after: sales tax applies to the discounted price the customer actually pays, not the pre-discount list price. Manufacturer coupons and rebates are sometimes treated differently from store-issued discounts, so check the receipt line order if the tax looks high.

Do I owe sales tax on an online purchase from another state?

In most cases yes. Since the 2018 Wayfair ruling, states can compel out-of-state sellers above certain sales thresholds to collect tax based on the buyer's address, so the checkout total should already include your local combined rate rather than the seller's.

How much tax will one extra percentage point add to my bill?

Exactly one percent of the subtotal, regardless of the base rate. On a 2,450 purchase, one additional point adds 24.50; on an 84.50 purchase it adds about 0.85. Multiply your subtotal by 0.01 to get the figure for any purchase.

Why is my state listed as having no sales tax but I still saw a charge?

Five states have no statewide sales tax, but some of them, including Alaska, still allow local governments to levy their own sales tax, so a purchase there can carry tax even though the state rate itself is zero.

Sales tax calculator

This calculator multiplies a subtotal by a single combined tax rate to show the tax charged and the final amount due at the register. It answers the question a shopper or a small business owner actually has before checkout: not the abstract statutory rate, but the dollars added to this specific purchase.

What counts as a normal combined rate

In the United States there is no federal sales tax, so the rate you enter is a combination of state, county, city and sometimes special-district rates stacked together. Five states charge no state-level sales tax at all, while several combined state-and-local rates land above 9% in parts of Louisiana, Tennessee and Arkansas, according to the Tax Foundation's state rate rankings.

A combined rate in the 6-8% range covers most US shoppers, so a rate you enter that is well outside that band, either near zero or above 10%, is worth double-checking against your specific city and county before you trust the total.

Outside the US, most countries use value-added tax instead, which is already baked into the shelf price rather than added at the till, so this calculator is built for the add-on model used in the US and Canada, not for VAT-style pricing.

Three purchases worked through

A 84.50 item at an 8.25% combined rate, typical of many Texas cities, adds 6.97 in tax for a total of 91.47. The same item taxed at a flat 10%, closer to some California city rates once local add-ons are included, adds 8.45 for a total of 92.95 — a 1.48 gap from a rate difference of under two points.

Buying six units of a 19.99 item at a 7% rate: the subtotal is 119.94, tax comes to 8.40 rounded, and the total due is 128.34. Pricing per unit and multiplying by quantity first, rather than taxing each unit separately and adding, gives the same answer here because tax is linear, but rounding differences can creep in on receipts that tax line by line.

A 2,450 equipment purchase taxed at 6.25% costs 153.13 in tax for a total of 2,603.13. Move the same purchase across a county line to a 7.25% rate and the tax rises to 177.63, a jump of exactly 24.50 — because one full percentage point on 2,450 is always 24.50, a useful shortcut for estimating how much a local rate difference is worth on a specific budget.

Why the sticker rate and your receipt rate can disagree

The formula here assumes every dollar of the subtotal is taxed at one flat rate, but real jurisdictions tax categories differently. Groceries, prescription medicine and clothing are commonly exempt or taxed at a reduced rate in many states, while restaurant meals and alcohol are often taxed at a surcharge above the general rate.

Sales tax holidays suspend the tax entirely on categories like school supplies or storm-preparedness items for a few days a year in states that offer them, which will make this calculator's output too high if you run a holiday purchase through the general rate.

Online purchases add another wrinkle: since the Supreme Court's 2018 Wayfair decision, states can require out-of-state sellers to collect tax based on the buyer's address rather than the seller's, so the applicable rate is usually the delivery address, not the store's home state.

Jurisdiction and timing notes

Local rates change more often than shoppers expect. Cities and counties frequently adjust district add-on rates at the start of a calendar quarter, so a rate you looked up six months ago may already be stale for a large purchase.

Some states cap the taxable amount on big-ticket items, such as boats or vehicles, at a maximum dollar figure regardless of price, which this general-purpose calculator does not model — check your state's specific vehicle or luxury-item rules separately.

Businesses that resell goods rather than consume them typically hold a resale certificate that exempts the purchase from sales tax entirely, shifting the tax obligation to the final retail sale instead. This calculator assumes a retail, taxable transaction throughout.

Frequently asked questions

How do I find the sales tax rate for my address?: Combine the state rate with any county, city and special-district rates that apply at your delivery or point-of-sale address. Many state department-of-revenue websites publish a lookup tool by ZIP code or address, since a single ZIP code can span more than one district rate.
Why did two receipts for the same item show different tax amounts?: The most common causes are different delivery addresses under destination-based tax rules, a category exemption applying to one purchase but not the other, or a rate change that took effect between the two purchase dates.
Is sales tax charged on the price after a discount or before it?: Generally after: sales tax applies to the discounted price the customer actually pays, not the pre-discount list price. Manufacturer coupons and rebates are sometimes treated differently from store-issued discounts, so check the receipt line order if the tax looks high.
Do I owe sales tax on an online purchase from another state?: In most cases yes. Since the 2018 Wayfair ruling, states can compel out-of-state sellers above certain sales thresholds to collect tax based on the buyer's address, so the checkout total should already include your local combined rate rather than the seller's.
How much tax will one extra percentage point add to my bill?: Exactly one percent of the subtotal, regardless of the base rate. On a 2,450 purchase, one additional point adds 24.50; on an 84.50 purchase it adds about 0.85. Multiply your subtotal by 0.01 to get the figure for any purchase.
Why is my state listed as having no sales tax but I still saw a charge?: Five states have no statewide sales tax, but some of them, including Alaska, still allow local governments to levy their own sales tax, so a purchase there can carry tax even though the state rate itself is zero.

Sources

Tax Foundation — State and Local Sales Tax Rates — Combined state and average local sales tax rates by state, 2025 edition; highest combined rates exceed 9% in Louisiana, Tennessee and Arkansas.
Supreme Court of the United States — South Dakota v. Wayfair, Inc. — 2018 decision permitting states to require remote sellers to collect sales tax based on the buyer's location.