How is US sales tax calculated?

US sales tax is calculated by multiplying the pre-tax price by the applicable combined rate (state + local). The formula is: Tax = Pre-Tax Price × (Rate ÷ 100) and Total = Pre-Tax Price + Tax. Unlike VAT in Europe, US sales tax is added on top of the listed price rather than being embedded in it — which is why prices in US stores are shown before tax.

What is the difference between state and local sales tax?

Every US state sets a statewide base sales tax rate. On top of that, counties, cities, and special districts can levy additional local sales taxes. For example, California's state rate is 7.25%, but Los Angeles County adds 2.25%, bringing the combined rate to 9.5% for most LA purchases. Five states — Alaska, Delaware, Montana, New Hampshire, and Oregon — have no state sales tax at all, though Alaska allows local taxes.

How do I reverse-calculate sales tax from a total price?

If you know the tax-included total and want to find the pre-tax price and tax amount, use the formula: Pre-Tax = Total ÷ (1 + Rate) and Tax = Total − Pre-Tax. Switch the calculator to Reverse mode, enter the total price, and the calculator does this automatically. This is useful for expense reporting, accounting reconciliation, or verifying a receipt.

Which US state has the highest sales tax rate?

California has the highest statewide base rate at 7.25%. However, combined state-plus-local rates are highest in Tennessee (9.55% average), Louisiana (9.55%), Arkansas (9.43%), Washington (9.24%), and Alabama (9.22%). The combined rate in some specific localities — like parts of Louisiana and Alabama — can reach 12% or higher.

Are groceries taxed in all US states?

No. Most US states exempt groceries from sales tax entirely, including California, New York, Texas, and Florida. Some states tax groceries at a reduced rate — Idaho taxes them at the full 6%, Mississippi at 7%, and Alabama at 3%. Kansas eliminated its grocery tax in 2024. Always check your specific state's rules, as the definition of "grocery" versus "prepared food" varies and prepared foods are typically taxed even in states that exempt groceries.

Do discounts affect the sales tax amount?

Yes. Sales tax is applied to the discounted price, not the original price. If an item costs $100 and has a 20% discount, tax is calculated on $80 — not $100. Manufacturer coupons and store discounts work the same way in most states. Enter your discount as a percentage or flat dollar amount in the calculator to see the accurate taxable base and tax amount.

What is the "Deduct" mode in this calculator?

Deduct mode is for situations where tax is already embedded in the price shown — such as a receipt where the line items include tax — and you need to split the price into its pre-tax and tax components. Enter the tax-inclusive amount, select your state, and the calculator extracts the tax using the formula Tax = Price − (Price ÷ (1 + Rate)). This is the same as Reverse mode and most useful for bookkeeping and expense reconciliation.

Can I use a custom tax rate instead of the state default?

Yes. Check the Use Custom Rate box and enter any rate you like. This is useful when you know your exact city or county combined rate, which may differ from the state average shown. Look up your precise local rate on your state's Department of Revenue website or on the Sales Tax Institute's jurisdiction database.

Does online shopping change what sales tax I owe?

Since the US Supreme Court's 2018 ruling in South Dakota v. Wayfair, online retailers must collect sales tax in states where they have "economic nexus" — typically $100,000 in sales or 200 transactions per year. In practice, most major online retailers now charge the applicable sales tax for your delivery address automatically. Small sellers below nexus thresholds may not charge tax, but technically you owe "use tax" to your state on untaxed purchases.

Sales Tax Calculator — Free USA Sales Tax Calculator by State

Q: Is shipping taxable?

It depends on the state. Many states tax shipping when it is charged as part of a taxable sale — including California, Texas, and New York. Others, like Florida and Virginia, generally do not tax separately-stated shipping charges. Use the Taxable Shipping toggle in the calculator to include or exclude shipping from the taxable base. When in doubt, check your state's Department of Revenue guidance.

How to Use the Sales Tax Calculator

US sales tax is one of the most fragmented tax systems in the world — 50 states, thousands of counties, and hundreds of cities each set their own rates, exemptions, and rules. Knowing your exact tax before checkout isn't just convenient; for business owners, freelancers, and anyone filing expense reports, it's a legal requirement. This calculator handles every scenario: adding tax to a price, working backward from a tax-included total, or extracting embedded tax from an all-in figure.

Choosing the Right Calculation Mode

The three-button mode selector at the top of the calculator changes everything about how your input is interpreted. Getting this right is the most important step.

Add Tax is the standard mode. Enter the price before tax, select your state, and the calculator adds the appropriate combined rate. This mirrors how US retailers display prices — the sticker price is pre-tax, and tax appears as a separate line at checkout.

Reverse Calculate is for when you have the tax-included total and need to find the original pre-tax price. This is common when reconciling receipts, calculating the true cost of an online order, or verifying a vendor invoice. The formula used is Pre-Tax = Total ÷ (1 + Rate).

Deduct Tax applies when tax is already embedded in a figure — for instance, a lump-sum payment that includes tax but shows no itemization. The math is identical to reverse calculation but the framing is different: you're deducting tax from a combined amount rather than verifying a standalone total.

The Formula Behind US Sales Tax

US sales tax uses simple multiplication — unlike VAT, there's no cascading effect across supply chains. The standard add-on formula is:

Tax = Pre-Tax Price × (Rate ÷ 100) Total = Pre-Tax Price + Tax

The combined rate is always state rate plus all applicable local rates. For example, Seattle, Washington applies the 6.5% state rate plus 3.9% city/county rate for a combined 10.4% — meaning a $500 purchase costs $552 total. The state comparison table in the calculator lets you see this effect instantly across all 50 states.

Step-by-Step Example

Marcus is buying two laptops at $849 each in Nashville, Tennessee. He has a $50 flat discount coupon. Tennessee's state rate is 7.00% and the average local rate is 2.55%, for a combined 9.55%.

Subtotal before discount: 2 × $849 = $1,698. After $50 discount: $1,648. Tax: $1,648 × 0.0955 = $157.38. Grand total: $1,648 + $157.38 = $1,805.38.

Of that $157.38 in tax, $115.36 goes to the state (7.00%) and $42.02 goes to local government (2.55%). The donut chart in the calculator makes this split immediately visible.

Understanding State vs Local Rates

Every rate shown in this calculator is a combined figure: the state base rate plus the average local rate for that state. In reality, your precise local rate depends on your exact street address. The averages shown are weighted means from the Tax Foundation's 2024–2025 data — accurate enough for budgeting and comparison, but always verify your specific city or county rate for precise transactional use.

Five states charge zero state sales tax: Alaska, Delaware, Montana, New Hampshire, and Oregon. Delaware and Oregon have no local sales tax either. Alaska, however, allows boroughs and cities to impose local taxes — some Alaskan municipalities charge up to 7.5%.

How Discounts Interact with Sales Tax

In all US states, sales tax applies to the final discounted price — not the original sticker price. A 20% off sale genuinely reduces your tax burden proportionally. Manufacturer rebates and mail-in rebates can work differently in some states: the tax may be calculated before the rebate is applied if the rebate comes from the manufacturer rather than the retailer.

Taxable vs Non-Taxable Shipping

Whether shipping is taxable varies by state. California, Texas, New York, and Illinois generally tax shipping charges when they're part of a taxable sale. Florida, Colorado, and Virginia typically do not tax separately-stated shipping charges. Use the "Tax shipping charges" toggle to model both scenarios and see the exact dollar difference.

Factors That Affect Your Actual Rate

Beyond the state you're in, the actual rate depends on your specific delivery or purchase location (destination-based vs origin-based sourcing), the type of product purchased (software, food, clothing, and medical devices each have unique exemption rules), whether you hold an exemption certificate (resellers, nonprofits, manufacturers), and whether the seller has economic nexus in your state. Clothing is exempt in New York (items under $110), Pennsylvania, Minnesota, and New Jersey. Prescription drugs are exempt everywhere.

Common Mistakes to Avoid

The most frequent error is using the state rate alone and ignoring local taxes — this understates actual cost by several percentage points in high-local-tax areas. A second common mistake is applying sales tax to the pre-discount price; US law is clear that the tax base is the amount the buyer actually pays. A third mistake is assuming online purchases are tax-free — since South Dakota v. Wayfair (2018), most significant online retailers charge the destination state's sales tax automatically.

Disclaimer

Tax rates reflect Tax Foundation data for 2024–2025 and represent statewide base rates plus weighted average local rates. Individual city, county, and special-district rates may vary. This calculator is for informational and planning purposes only. For binding tax advice, consult a licensed CPA or your state's Department of Revenue.

Sales Tax Calculator