Sales Tax Calculator: Find State & Local Tax Fast

Sales Tax Calculator: How to Calculate Tax on Any Purchase

Quick summary: A sales tax calculator applies the formula Tax = Price × (Rate ÷ 100) to find the tax owed on a purchase, then adds it to the price for your total. In 2026, five US states — Alaska, Delaware, Montana, New Hampshire, and Oregon (remembered by the acronym “NOMAD”) — charge no statewide sales tax at all, while the average combined state-and-local rate nationally sits around 6.6%.

Whether you’re budgeting a big purchase, checking whether a receipt charged you correctly, or pricing products for your own small business, a sales tax calculator turns a simple percentage into an exact dollar figure. This guide covers the forward and reverse sales tax formulas, current 2026 state rate data, the difference between origin-based and destination-based taxation, and several fully worked examples.

What Is a Sales Tax Calculator?

A sales tax calculator is a tool that determines the amount of sales tax added to a purchase and the total price you’ll actually pay at checkout. You enter the pre-tax price of an item and your applicable combined tax rate — made up of state, county, city, and sometimes special district components — and the calculator instantly tells you the tax charged and the final all-in price (calculatorbank.com). Sales tax itself is a consumption tax imposed by state and local governments, collected once at the final point of sale and paid entirely by the end consumer (calculatorbank.com; calculations.tools).

The Sales Tax Formula

The standard forward formula is:

Sales Tax Amount = Price × (Tax Rate ÷ 100)

For example, a $50 item at a 7.5% tax rate: $50 × 0.075 = $3.75 in tax, for a total of $53.75 (quickbooks.intuit.com).

More precisely, since most jurisdictions layer a local rate on top of the state rate, the full formula is:

Sales Tax Amount = Price × [State Rate (decimal) + Local Rate (decimal)]

(taxhero.net)

The Reverse Sales Tax Formula

Sometimes you know the total amount paid and need to work backward to find the original pre-tax price — for example, when reconciling a receipt. The formula is:

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

For example, $108.94 paid in California at an 8.94% combined rate: $108.94 ÷ 1.0894 = $100.00 pre-tax (ustaxcalc.com). It’s worth noting explicitly: you divide by (1 + rate), you do not simply subtract the tax rate percentage from the total — that shortcut produces an incorrect result (fasttaxcalc.com).

Which States Have No Sales Tax?

As of 2026, five US states charge no statewide general sales tax — a group commonly remembered using the acronym NOMAD:

New Hampshire
Oregon
Montana
Alaska
Delaware

(ustaxcalc.com; calculations.tools)

In four of these states — Delaware, Montana, New Hampshire, and Oregon — there is no sales tax at any level, state or local. Alaska is the exception: while it has no state sales tax, it allows local municipalities to levy their own, with some Alaska cities charging local rates as high as 7.5%, and an average local rate around 1.82% statewide (ustaxcalc.com; calcsharp.com).

Highest and Average Combined Sales Tax Rates

According to Tax Foundation data cited across multiple 2026 sales tax resources, the average combined state-and-local sales tax rate in the US is approximately 6.6% (calculations.tools). At the top end, Louisiana and Tennessee are tied for the highest combined state-and-local rate in the country, at 9.55% — Louisiana’s figure breaks down to a 4.45% state rate plus an average local rate of 5.10% (ustaxcalc.com; calculations.tools).

California has the highest state-level rate in the country at 7.25% (which itself includes a mandatory 1.25% local add-on) — but combined with additional district taxes, cities like Los Angeles can see total rates exceed 10% (ustaxcalc.com; fasttaxcalc.com).

Worked Examples

Example 1: Basic purchase calculation

You’re buying a $200 item in a state with a 7.25% rate (California’s state rate).

Calculation: Tax = $200 × 0.0725 = $14.50 Total = $200 + $14.50 = $214.50

(calculations.tools)

Example 2: A high-tax city with district add-ons

You’re buying a $500 item in the City of Los Angeles, where the combined rate is 9.75% (7.25% CA state + 2.50% LA County district taxes, including Metro transit and homelessness funding measures, effective per CDTFA rate updates).

Calculation: Tax = $500 × 0.0975 = $48.75 Total = $500 + $48.75 = $548.75

(ustax.tools)

Example 3: Reverse-calculating from a receipt total

You paid $108.94 total for an item in an area with an 8.94% combined rate, and want to know the original pre-tax price.

Calculation: Pre-Tax Price = $108.94 ÷ 1.0894 = $100.00

(ustaxcalc.com)

Example 4: A no-sales-tax state

You buy a $300 item in New Hampshire, one of the five NOMAD states.

Calculation: Since New Hampshire has no state or local sales tax, Tax = $0, and the Total = $300 — exactly the sticker price.

Origin-Based vs. Destination-Based Sales Tax

This is one of the more confusing aspects of US sales tax, and it directly affects which rate applies to a given transaction:

Destination-based sourcing — the tax rate is determined by the buyer’s location (where the item is shipped or delivered). This is the system used by most states (fasttaxcalc.com; ustax.tools).
Origin-based sourcing — the tax rate is determined by the seller’s location instead. A smaller number of states — including Texas, Pennsylvania, and Ohio — use this system, at least for certain transaction types (ustax.tools; ustaxcalc.com).

For most online and shipped purchases, destination-based sourcing is now the norm nationally, meaning the rate that applies is generally based on where the buyer receives the item, not where the seller is located (fasttaxcalc.com).

What Products Are Actually Taxed?

Sales tax rules vary significantly by state on exactly which goods and services are taxable. A few notable, evolving examples:

Groceries are often exempt or taxed at a reduced rate in many states — for example, Kansas completed a three-year phase-out of its state grocery sales tax, reducing the rate from 2% to 0% effective April 2026 (fasttaxcalc.com).
Digital goods are an expanding area of taxation — some states are extending sales tax to items like in-game “skins” and other virtual goods as digital commerce grows (taxhero.net).
Clothing, electronics, furniture, and general household goods are fully taxable in essentially all states that charge sales tax (ustaxcalc.com).

Because these rules vary so much by state — and even by city or county within a state — a general combined-rate estimate is useful for budgeting, but exact compliance for business filing purposes requires checking state-specific product exemption rules directly (fasttaxcalc.com).

Sales Tax and Federal Tax Deductions

For taxpayers who itemize deductions on their federal return, state and local sales tax paid can, in some cases, be deducted (as an alternative to deducting state income tax) under the SALT (State and Local Tax) deduction. The combined SALT deduction — covering property tax plus the greater of state income tax or sales tax — is subject to a federal cap, which for 2026 rises to $40,400, phasing down for higher earners above certain income thresholds (ustax.tools).

FAQs

What is the formula to calculate sales tax?

The standard formula is Sales Tax Amount = Price × (Tax Rate ÷ 100). To find the total price including tax, simply add that tax amount back to the original price.

Which US states have no sales tax?

Five states charge no statewide general sales tax as of 2026: New Hampshire, Oregon, Montana, Alaska, and Delaware — remembered by the acronym NOMAD. Alaska, however, allows local municipalities to levy their own sales taxes.

What is the average combined sales tax rate in the US?

According to Tax Foundation data, the average combined state-and-local sales tax rate nationally is approximately 6.6% as of 2026, though this varies significantly by state and locality.

How do I calculate the pre-tax price from a total that already includes tax?

Divide the tax-inclusive total by (1 + the tax rate as a decimal). For example, $108.94 divided by 1.0894 (an 8.94% rate) equals a $100.00 pre-tax price. You should never simply subtract the tax percentage from the total.

What’s the difference between origin-based and destination-based sales tax?

Destination-based sourcing applies the tax rate of the buyer’s location, while origin-based sourcing applies the tax rate of the seller’s location. Most states use destination-based sourcing, though a few, including Texas, Pennsylvania, and Ohio, use origin-based rules in certain contexts.

Related Calculators

Conclusion

A sales tax calculator takes the simple percentage math behind every checkout total — Price × Tax Rate — and applies it accurately across the genuinely complex patchwork of US state, county, and city tax rates. Whether you’re budgeting a purchase in a high-tax city like Los Angeles, reverse-engineering a receipt total, or taking advantage of shopping in one of the five NOMAD states with no sales tax at all, understanding both the forward and reverse sales tax formulas means you’ll always know exactly what you’re actually paying — and why.