Tax Tools

Sales Tax Calculator

Add sales tax, remove tax from a total, or estimate pre-tax price with state sales tax calculators and reverse tax math.

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Add or remove tax — any rate, any amount

Pre-Tax Price ($)

Tax Rate (%)

State base rate

Sales Tax Guide

3 questions

Which US states have no sales tax?

Five states have no statewide sales tax: Oregon, Montana, New Hampshire, Delaware, and Alaska. Alaska allows local municipalities to impose sales tax, so some areas still have rates up to 7%.

How do I calculate tax-inclusive price?

To find the pre-tax price from a tax-inclusive total, divide by (1 + tax rate). For example, a $108.50 total with 8.5% tax: $108.50 ÷ 1.085 = $100 pre-tax. The tax portion is $8.50.

Is sales tax charged on services?

It depends on the state. Most states tax tangible goods but not services. Some states (Hawaii, New Mexico, South Dakota) tax most services. Professional services like legal, medical, and accounting are generally exempt nationwide.

Finance Guide

Sales Tax Calculator Guide: How Sales Tax Works, Reverse Math & Smart Purchase Planning

A practical guide to sales tax — how to compute it, how to reverse the math to find pre-tax price, what state-by-state rates look like, and the rules that change for online, food, and clothing purchases.

Written by Calculixy Editorial Team · 20 years in financial servicesReviewed by a certified tax professionalUpdated: May 2026

From the Underwriting Desk

Sales tax is the most common math Americans do — and the most often miscalculated. Shoppers know "tax was added" but rarely check whether the receipt's calculation is correct. Businesses misquote pre-tax prices when customers ask. Travelers cross state lines and pay unexpected extra. The Sales Tax Calculator handles all three problems by doing the arithmetic precisely in both directions: from pre-tax price to total, and from total back to pre-tax price.

What this calculator does

The Sales Tax Calculator computes the tax amount and final total when you enter a pre-tax price and a tax rate. It also works in reverse — given a total that includes tax, it backs out the pre-tax price and the tax amount. This is useful for budgeting against advertised after-tax prices, verifying receipts, comparing purchases across jurisdictions, and reverse-engineering business margins.

Sales tax in the US is collected by states (and sometimes counties and cities), and the rules vary widely. The calculator assumes a single combined rate you input. For accurate results, look up the combined state + local rate for the specific ZIP code where the purchase will be made, or use the rate printed on a recent receipt.

When to use this calculator

To compute the tax amount and total on a planned purchase
To reverse-calculate the pre-tax price from a receipt or total-inclusive listing
To compare the cost of buying online vs. in-store across different tax jurisdictions
To verify a receipt's tax calculation
To estimate sales tax on a large purchase (car, appliance, furniture) before checkout
To plan a multi-state shopping trip in border areas with different rates

The sales tax formulas

Forward calculation (pre-tax price to total)

Tax Amount = Pre-tax Price × Tax Rate Total = Pre-tax Price + Tax Amount Total = Pre-tax Price × (1 + Tax Rate)

Reverse calculation (total to pre-tax price)

Pre-tax Price = Total ÷ (1 + Tax Rate) Tax Amount = Total − Pre-tax Price

Variable definitions

Pre-tax Price = The item's listed price before sales tax (the price on the shelf, in most US states)
Tax Rate = The applicable combined sales tax rate, expressed as a decimal (8.25% = 0.0825)
Tax Amount = The dollar amount of sales tax owed
Total = The final amount paid, including tax

Common reversal mistake: Don't subtract the tax rate from the total. If a $100 total includes 8% tax, the pre-tax price is NOT $100 − 8% = $92. It's $100 ÷ 1.08 = $92.59. The difference of 59 cents is small at $100, but at $50,000 (a vehicle), the error is $295.

Step-by-step example

Forward: Computing tax on a planned purchase

You're buying a $1,499 laptop in a state with 7.25% sales tax.

Tax = $1,499 × 0.0725 = $108.68 Total = $1,499 + $108.68 = $1,607.68

Plan for $1,607.68 at checkout, not $1,499.

Reverse: Backing out tax from a total

A contractor charges $5,400 "all-in" for a project in a 6% sales tax jurisdiction. To understand the pre-tax materials/labor cost:

Pre-tax = $5,400 ÷ 1.06 = $5,094.34 Tax = $5,400 − $5,094.34 = $305.66

The contractor's pre-tax revenue is $5,094.34. The remaining $305.66 will go to the state.

Combining state and local rates

If a state has a 4% sales tax and a county adds 2% with a city adding 1%, the combined rate is 7%. Always combine before applying — don't compute and apply each rate separately, as that produces compounding errors.

US sales tax basics by state

Sales tax rules are entirely state-level, with significant local variation. Some general patterns:

States with no sales tax

Alaska (though many municipalities add local sales tax)
Delaware
Montana (with some local exceptions)
New Hampshire
Oregon

States with high statewide rates

California: 7.25% state, often 9%–10% combined with local
Indiana: 7% state
Mississippi, Rhode Island, Tennessee: 7% state
Combined rates in Chicago, Seattle, and parts of LA County can exceed 10.25%

States with grocery exemptions

Most states either fully exempt unprepared groceries from sales tax or tax them at a reduced rate. Alabama, Hawaii, Idaho, Kansas, Mississippi, Oklahoma, and South Dakota currently tax groceries at their full rate. Several others (Arkansas, Illinois, Missouri, Tennessee, Utah, Virginia) tax groceries at a reduced rate.

States with clothing exemptions

Some states (Minnesota, Pennsylvania, New Jersey, parts of New York) exempt most clothing from sales tax. Others apply standard rates.

Look up actual rates: Sales tax rates change. State revenue department websites or services like TaxJar maintain current rate lookups by ZIP code. The calculator does the math correctly — you have to provide the right rate.

Online sales tax: the post-Wayfair landscape

Before 2018, online sellers were generally required to collect sales tax only in states where they had a physical presence. The Supreme Court's South Dakota v. Wayfair decision changed this — states can now require online sellers to collect sales tax even without physical presence, based on economic thresholds (typically $100,000 in sales or 200 transactions in the state per year).

The practical effect: most major online retailers (Amazon, Walmart.com, Target.com, eBay) now charge sales tax at the destination rate for almost every order. Small online sellers may still vary, and marketplace platforms have varying compliance.

Use tax

If you buy online and sales tax isn't collected, technically you owe "use tax" to your state at the same rate. In practice, individual taxpayers rarely report use tax on small purchases. Businesses are more strictly audited. For large purchases (vehicles, equipment) registered or used in a state, use tax is typically enforced through registration or licensing.

Real-world use cases

1. Vehicle purchase across state lines

If you buy a car in a no-tax state but register it in your home state, you'll usually owe your home state's sales/use tax at registration. The dealer may or may not collect it; the DMV will. The calculator helps you estimate the eventual cost. Pair with our Auto Loan Calculator to see how tax affects your financed amount.

2. Big-ticket budget planning

A $5,000 appliance with 8% sales tax means $5,400 at checkout. For a $25,000 wedding catering bill at 9% tax, plan for $27,250. Adding tax in advance prevents budget surprises.

3. Comparing two prices across jurisdictions

Online retailer A: $899, 6.5% tax. Online retailer B: $920, no tax (smaller seller, no economic nexus). Calculator shows: A is $957.44 total, B is $920 — so B is actually cheaper despite the higher headline price.

4. Verifying a receipt

A restaurant bill shows $87.50 subtotal, $7.88 tax, $95.38 total. Is the tax correct? Calculator: $87.50 × 0.09 = $7.88. Yes, the 9% tax is computed correctly. (You can also reverse-check: $95.38 ÷ 1.09 = $87.50.)

5. Calculating tip on the right base

If you're tipping on a meal, should you tip on the pre-tax or post-tax amount? Etiquette varies, but most guides recommend tipping on pre-tax. Our Tip Calculator handles this scenario directly.

Common mistakes

Subtracting the percentage instead of dividing. $100 total at 8% tax reverses to $92.59, not $92. The error compounds as totals grow.
Applying state and local rates separately. A 4% state tax and 3% local tax is a 7% combined tax — applied once. Applying 4% then 3% produces a slightly higher result and is wrong.
Using the wrong jurisdiction's rate. Sales tax in the US is destination-based for most transactions, meaning the buyer's location determines the rate. Buying online from California to ship to Florida means Florida tax applies, not California.
Forgetting exempt categories. Groceries, clothing, prescription drugs, and certain services are exempt in some states. Don't assume everything is taxable.
Confusing sales tax with VAT. Most countries outside the US use Value-Added Tax (VAT), which is computed and embedded into prices differently. International purchases may show VAT-inclusive prices that the calculator interprets correctly if you treat VAT as the "tax rate" input.
Skipping tax on private-party purchases. Buying a used car from an individual still typically owes sales tax at registration in most states, even though no business collects it at the sale.
Not factoring tax into trade-in math. In most states, the trade-in value reduces the tax base for the new purchase. Trading in a $10,000 car against a $35,000 new car at 7% tax: you pay tax on $25,000, not $35,000.

Frequently asked questions

How do I calculate sales tax?

Multiply the pre-tax price by the tax rate (as a decimal). A $50 purchase at 8% tax: $50 × 0.08 = $4 tax, total $54.

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

Divide the total by (1 + tax rate). A $108 total at 8% tax reverses to $108 ÷ 1.08 = $100 pre-tax, $8 tax.

What's the average sales tax in the US?

The average combined state + local sales tax across the US is approximately 7%, but the range is wide — from 0% in tax-free states to over 10% in some cities. Always look up your local rate before relying on a national average.

Do I owe sales tax on online purchases?

For most online purchases from major retailers, sales tax is collected automatically at your destination rate. If a smaller seller doesn't collect it, you technically owe use tax to your state. In practice, individual use tax compliance is rare and minimally enforced for everyday purchases.

Are groceries taxed?

It depends on the state. Most states either exempt unprepared groceries or tax them at a reduced rate. Prepared food (restaurant meals, hot deli items) is almost universally taxable at the full rate.

Why do I sometimes pay no tax?

Possible reasons: the state has no sales tax (Delaware, Oregon, etc.), the item is in an exempt category (clothing in some states, prescription drugs), the seller doesn't have to collect tax in your state, or the transaction was tax-exempt for other reasons (resale, nonprofit, government).

What's a "use tax" notice on my state tax return?

If you bought items online without paying sales tax during the year, you may owe use tax to your state at the same rate. Some state tax forms have a line for self-reporting this. Most individual filers leave it blank for small purchases.

Can sales tax be deducted on federal taxes?

Yes, but only if you itemize and choose to deduct sales tax instead of state income tax. For most filers in states with income tax, deducting state income tax is the better choice. Filers in no-income-tax states (Texas, Florida, etc.) often benefit from the sales tax deduction. Discuss with a tax professional.

Related Calculixy calculators

State sales tax calculators

From the editorial desk: Sales tax is invisible until it isn't. Adding it up correctly before checkout prevents budget surprises. Reverse-engineering it correctly after the fact catches errors and lets you compare options on a true cost basis. The math is simple, but the discipline of doing it consistently is what separates careful shoppers from people who later wonder where their money went.

Calculixy's Sales Tax Calculator provides estimates for educational use only and does not constitute tax advice. Sales tax rates and rules vary by state, county, and city, and change over time. Verify the current applicable rate with your state's revenue department or a qualified tax professional before making important purchase decisions. All calculations run locally in your browser; Calculixy does not collect or transmit the values you enter.