Sales Tax Calculator
Add sales tax to a price using your state's average combined rate, or back a pre-tax subtotal out of a tax-included total. Covers all 50 states plus DC.
Calculate sales tax
Most of the time you're adding tax to a price. Backing tax out of a total is for the rare case where you only have a tax-included receipt total.
The listed price before tax is added at checkout.
Sets the estimated rate below to your state's average.
Pre-filled with your state's average combined state + local rate — type in your exact local rate if you know it.
About this rate
California's statewide rate is 7.25%, and the average combined rate with local (county/city/district) taxes added is 9.03%. Your actual rate depends on the exact city and county where the sale happens — check your receipt or your local tax authority for the precise figure.
Total with sales tax
$109.03
Rate applied: 9.03%
Pre-tax subtotal
$100
Sales tax
$9.03
Total with tax
$109.03
Breakdown
Estimate calculated from the numbers you entered. This is not financial, tax, or legal advice — always consult a qualified professional before making significant financial decisions.
What this Sales Tax Calculator does
Calculates US sales tax in both directions: add tax to a pre-tax price to see what you’ll pay at checkout, or back a pre-tax subtotal out of a tax-included total. Pick your state to pre-fill an estimated combined rate (state + average local tax) for all 50 states and DC, or type in your own rate if you know the exact one for your city and county.
Sales tax isn’t VAT
If you’re used to a value-added tax that’s already folded into the price you see on the shelf, US sales tax works differently in three ways. First, it’s added on top of the listed price at checkout rather than included in it — the sticker price is the pre-tax price. Second, there’s no single national rate: it’s set by each state, and in most states counties, cities, and special districts can stack their own local rate on top, so the same item can cost a different amount of tax a few miles apart. Third, sales tax is a single-stage tax collected only from the final consumer — there’s no multi-stage input-tax-credit mechanism running through the supply chain the way VAT has, so businesses don’t need to track a tax paid on their own purchases the way VAT-registered businesses do.
The two formulas
Add sales tax (starting from the pre-tax price)
Total = Subtotal × (1 + Rate / 100)Back tax out of a total (starting from the total)
Subtotal = Total / (1 + Rate / 100)In both directions, the sales tax amount is always the difference between the total and the subtotal: Sales Tax = Total − Subtotal.
A worked example
Say you’re buying something priced at $100 in California, where the average combined state and local rate is about 9.03%. At checkout you’d pay $9.03 in sales tax, for a total of $109.03. Working backward: if a receipt only shows a total of $109.03 at that same 9.03% rate, the pre-tax subtotal was $109.03 / 1.0903 = $100 — not $109.03 minus 9.03% directly, which would incorrectly give $99.19.
Common mistakes
- Subtracting the rate directly from a total: as in the example above, this understates the pre-tax subtotal. Divide by (1 + rate/100); don’t multiply by (1 − rate/100).
- Treating the state rate as the full rate: the state rate alone often understates what you’ll actually pay once county, city, or district taxes are stacked on top — use the combined rate, or your exact local rate if you know it.
- Assuming a listed price includes tax: unlike VAT-included pricing, a US sticker or listed price is normally pre-tax — budget for tax to be added on top at checkout.
- Ignoring exemptions: groceries, prescription drugs, and other categories are exempt or taxed at a reduced rate in many states — this calculator applies one flat rate, so it won’t reflect item-specific exemptions.
Frequently asked questions
Why doesn’t the price on the shelf already include sales tax?
It’s just a different convention than VAT-based systems. In the US, retailers advertise and price items before tax because sales tax rates vary so much by location — the same national chain would need a different sticker price in every city if tax were baked in. Instead, the tax is calculated at the register based on where the sale happens, and added as a separate line on your receipt.
Why is the rate for my state an estimate instead of an exact number?
Because US sales tax isn’t a single state-level number the way VAT is a single national number. Most states let counties, cities, and special districts (transit authorities, stadium districts, etc.) add their own local sales tax on top of the state rate. The rate this calculator pre-fills is the state’s population-weighted average combined rate, which is a good planning estimate — but the exact rate for a specific purchase depends on the exact city and county it happens in. If you know your local rate, type it directly into the rate field to override the estimate.
Which states have no sales tax?
Alaska, Delaware, Montana, New Hampshire, and Oregon have no statewide sales tax. Delaware, Montana, and New Hampshire also have no local sales taxes, so shopping there means no sales tax at all. Alaska is the exception: while it has no state-level rate, many Alaska municipalities levy their own local sales tax, so purchases there can still carry some tax depending on where you are.
What’s the difference between "add sales tax" and "back tax out of a total"?
Adding sales tax is the everyday case: you have a pre-tax price (what’s on the shelf or in a cart) and want to know what you’ll actually pay at checkout once tax is added. Backing tax out of a total is the reverse and much less common — you only have a final, tax-included number (say, from a receipt or an invoice line that bundles tax in) and need to reconstruct what the pre-tax subtotal was. Unlike a VAT receipt, where the tax-inclusive total is the normal starting point, a US receipt usually already itemizes the pre-tax subtotal and the tax separately, so this reverse mode is mainly useful for edge cases like reading an all-in total from a different source.
Why can’t I just subtract the tax percentage from a tax-included total?
Because the tax rate applies to the pre-tax subtotal, not to the final total. If a $109.03 total includes a 9.03% tax, subtracting 9.03% of $109.03 directly gives you $99.19 — which is wrong. The correct approach divides the total by (1 + rate), so $109.03 / 1.0903 = $100.00 exactly. This calculator’s "back tax out of a total" mode does that division for you automatically.
Does this calculator account for items that are exempt from sales tax?
No — it applies a single flat rate to the full amount you enter. In practice, many states exempt or apply reduced rates to specific categories, most commonly groceries, prescription drugs, and sometimes clothing, and those exemptions vary a lot state by state. If you’re calculating tax on a mixed cart that includes exempt items, you’d need to apply this calculator separately to just the taxable portion.
Does this include use tax on online or out-of-state purchases?
Not directly, but the math is the same. Most states also charge a "use tax" — functionally identical to sales tax — on purchases made from an out-of-state or online seller that didn’t collect sales tax at checkout, which you’re technically responsible for reporting yourself. If you need to estimate that, use the "add sales tax" mode with your state’s rate the same way you would for an in-state purchase.
What actually moves this number
Specific levers, and roughly what each one is worth. Not “save more” — the things that change the figure above by an amount you can measure.
Use the combined rate at the delivery address
State rates are close to useless for an actual purchase. Louisiana's 5% state rate sits under a 10.13% average combined rate, and rates change across a county line. Your revenue department publishes the local figure.
Watch the tax on a car bought out of state
You generally pay use tax at your home rate when you register it, not the seller's rate. Buying in a low-tax state and registering in a high-tax one saves nothing and occasionally surprises people at the DMV.
Time large purchases around a sales tax holiday
Many states exempt qualifying items below a price cap for a weekend, usually before the school year. On several thousand dollars of purchases that is real money for a scheduling decision.
Check the grocery exemption where you shop
Most states exempt or reduce the rate on unprepared food, and the line between exempt groceries and taxable prepared food is drawn differently everywhere — sometimes on whether a product contains flour.
What this calculator does not cover
Every calculator simplifies, and the useful thing is knowing exactly where. These are the specific gaps between this estimate and your real situation:
- It uses each state's population-weighted average combined rate. Actual rates are set by county, city, and special districts, and within a single state can span more than two percentage points.
- Exemptions are not modeled. Most states exempt or reduce the rate on unprepared groceries and prescription drugs, and a few exempt clothing — with statutory boundaries that are genuinely peculiar.
- Sales tax holidays are not modeled. Many states exempt qualifying purchases below a price cap for a weekend each year.
- For an exact amount, use the combined rate at the delivery address, which your state or county revenue department publishes.
For anything that turns on an exact figure, use the primary sources below or a qualified professional. How these limits are decided and disclosed is described in the editorial standards.
Sources