How to Calculate Sales Tax: A Complete Guide for Every US State

What Is Sales Tax?

Sales tax is a consumption tax imposed by state and local governments on the sale of goods and certain services. When you purchase an item, the seller collects the tax at the point of sale and remits it to the appropriate government agency. In the United States, sales tax is governed at the state level, which is why rates vary so dramatically across the country — from zero in five states to over 10% in some jurisdictions.

Understanding how sales tax is calculated is essential for both consumers who want to budget accurately and small business owners who need to collect and remit tax correctly. This guide covers everything you need to know, from the basic formula to state-specific rates and special rules for online shopping.

The Sales Tax Formula

Calculating sales tax is straightforward. The basic formula is:

For example, if you buy a laptop for $999 in California (7.25% state rate):

• Sales Tax = $999 × 0.0725 = $72.43
• Total Price = $999 + $72.43 = $1,071.43

To calculate the total price in one step, you can use this shortcut:

Using our laptop example: $999 × 1.0725 = $1,071.43 — same result in fewer steps.

Finding the Pre-Tax Price

Sometimes you know the total price and need to find the original price before tax. This is the reverse calculation:

If your receipt shows $85.50 total and the local tax rate is 7%:

• Pre-Tax Price = $85.50 ÷ 1.07 = $79.91
• Sales Tax Paid = $85.50 - $79.91 = $5.59

This is useful for business expense reports, where you need to separate the tax from the purchase price for accounting purposes.

Complete US State Sales Tax Rates

The following table shows the base state sales tax rate for all 50 states plus Washington, D.C. as of 2026. Note that many states allow additional local taxes (county, city, district), so the actual rate you pay may be higher than the state rate shown here.

* Alaska has no state sales tax but allows local jurisdictions to levy their own (averaging 1.76%). Rates subject to change; verify with your state's department of revenue.

The Five Tax-Free States

Five states do not levy a statewide sales tax, making them attractive for large purchases:

1. Alaska — No state sales tax, but many municipalities charge local sales tax (average 1.76%). Anchorage charges 0%, while some smaller towns charge up to 7%.
2. Delaware — Truly tax-free at all levels. No state or local sales tax. Delaware is a popular shopping destination for residents of neighboring Pennsylvania, Maryland, and New Jersey.
3. Montana — No general sales tax. However, some resort areas charge a limited local-option tax on tourism-related purchases (lodging, car rentals, restaurant meals).
4. New Hampshire — No state or local sales tax. The state motto "Live Free or Die" extends to shopping — making it a major retail draw for Massachusetts residents.
5. Oregon — No state or local sales tax. Portland-area residents frequently cross the Columbia River to Vancouver, Washington for tax-free shopping, ironically avoiding Washington's 6.5% state rate.

Understanding Combined Tax Rates

The state rate is only the starting point. Most states allow local governments — counties, cities, transit authorities, and special districts — to add their own taxes on top of the state rate. The total you pay is called the combined rate.

States with the highest combined average rates include:

• Louisiana — 9.55% combined average
• Tennessee — 9.55% combined average
• Arkansas — 9.45% combined average
• Washington — 9.29% combined average
• Alabama — 9.26% combined average

Some specific cities have even higher combined rates. Birmingham, AL reaches 10%; Seattle, WA is 10.35%; and some areas in Louisiana exceed 11%.

Online Shopping and Sales Tax

One of the biggest changes in sales tax in recent years affects online purchases. Prior to 2018, many online retailers did not collect sales tax unless they had a physical presence (nexus) in the buyer's state. This changed dramatically with a landmark Supreme Court decision.

The Wayfair Decision (2018)

In South Dakota v. Wayfair, Inc. (2018), the U.S. Supreme Court ruled that states can require online retailers to collect sales tax even without a physical presence, based on economic nexus. The standard threshold established by the decision — and since adopted by most states — is:

• $100,000 or more in annual sales in the state, OR
• 200 or more separate transactions in the state

In practice, this means that virtually all major online retailers — Amazon, Walmart, Target, eBay, Etsy — now collect sales tax in nearly every state that imposes one. Small sellers below the nexus threshold generally do not need to collect tax.

What This Means for You as a Consumer

• Most online purchases are now taxed. When you buy from major retailers, sales tax is calculated automatically at checkout based on your shipping address.
• Marketplace facilitators collect tax. Amazon, eBay, and similar platforms collect and remit tax on behalf of third-party sellers using their platforms.
• Small sellers may not charge tax. Purchases from small independent sellers on platforms like Etsy or independent websites may still be tax-free if the seller is below the economic nexus threshold.
• Use tax obligations. If a seller does not collect sales tax on your purchase, most states require you to report and pay the equivalent "use tax" on your state tax return. In practice, few consumers comply with this requirement.

What Is Tax-Exempt?

Not everything is subject to sales tax. Common exemptions include:

Groceries

Approximately 13 states fully exempt groceries from sales tax. Another 30+ states tax groceries at a reduced rate or exempt specific food items. States that fully tax groceries at the standard rate include Alabama, Hawaii, Idaho, Kansas, Mississippi, Oklahoma, South Dakota, and Wyoming. Louisiana reduced its grocery tax to 0% starting in 2025.

Prescription Medications

All 50 states and Washington, D.C. exempt prescription medications from sales tax. Over-the-counter medications are generally taxable, though some states provide reduced rates or exemptions.

Clothing

Most states tax clothing, but several provide exemptions or reduced rates. Pennsylvania, Minnesota, New Jersey, and Vermont exempt most clothing entirely. New York exempts clothing under $110 per item. Massachusetts and Connecticut hold periodic "sales tax holidays" for clothing and school supplies.

Digital Products and Services

The taxation of digital downloads, streaming services, and SaaS products varies widely. Some states tax digital goods the same as physical goods, others have specific rules, and a few exempt them entirely. This area of tax law is rapidly evolving.

Sales Tax Holidays

Many states offer annual sales tax holidays — temporary periods when specific items are exempt from sales tax. These are typically timed around back-to-school season (July–August) but can also apply to emergency preparedness supplies, Energy Star appliances, or hurricane preparedness items.

Common tax-free items during these holidays include:

• Clothing and footwear (usually under a per-item price cap of $75–$100)
• School supplies (under $20–$50 per item)
• Computers and accessories (under $1,000–$1,500)
• Energy Star appliances (under $2,500)

Check your state's department of revenue website for current sales tax holiday dates and eligible items, as they change annually.

Sales Tax for Small Business Owners

If you sell goods or services, understanding sales tax collection is a legal requirement. Key obligations include:

1. Register for a sales tax permit in every state where you have nexus (physical or economic).
2. Collect the correct rate at the point of sale, including state, county, city, and any special district taxes.
3. File returns on schedule — most states require monthly, quarterly, or annual filings depending on your sales volume.
4. Keep detailed records of all taxable and exempt sales, as well as tax collected and remitted.
5. Understand exemption certificates — buyers who qualify for tax-exempt purchases (nonprofits, resellers, manufacturers) must provide valid exemption certificates.

Practical Calculation Examples

Example 1: Buying a TV in Texas

• TV price: $799.99
• Texas state rate: 6.25%
• Dallas city rate: 2.00%
• Combined rate: 8.25%
• Tax: $799.99 × 0.0825 = $65.00
• Total: $864.99

Example 2: Restaurant Meal in New York City

• Meal price: $45.00
• NYS rate: 4.00%
• NYC rate: 4.50%
• Combined rate: 8.875%
• Tax: $45.00 × 0.08875 = $3.99
• Total: $48.99

Example 3: Online Purchase from Oregon (No Tax)

• Item price: $150.00
• Oregon state rate: 0%
• Total: $150.00

Conclusion

Sales tax affects nearly every purchase you make, and the rules vary dramatically depending on where you live and what you are buying. Understanding the basic formula, knowing your state's rate, and being aware of exemptions and holidays can save you significant money — especially on large purchases.

For quick, accurate calculations across any US state and zip code, use our free sales tax calculator. Simply enter the purchase amount and location to get the exact tax and total instantly.

Frequently Asked Questions