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Financial · Taxes Formula verified

Sales Tax Calculator

Add sales tax to a price to see the total, or work backward from a receipt total to find the pre-tax price and how much tax you paid.

Direction
$
$0$1,000$2,000
%
0%7.5%15%
On-screen number pad
Tap to type into the highlighted field
Total price
$86.60
Tax added
Price before tax
$80.00
Sales tax
$6.60

Step-by-step proofCheck by hand
This is a general sales-tax estimate, not a jurisdictional lookup. Sales tax rates are set independently by each state, county and city, and often combine several rates into one "combined" rate. This calculator applies whatever rate you enter — it does not know your specific address. Some items (groceries, prescription drugs, clothing in some states) are taxed at a reduced rate or exempt entirely. Verify the exact rate and any exemptions with your state or local taxing authority before relying on the result.
Visual breakdown

Price vs. tax

Price before tax Sales tax

The bar shows the pre-tax price and the tax as shares of the final total — the same two numbers as the result panel, drawn to scale.

How sales tax is calculated

Sales tax is a percentage of the pre-tax price, added on top: multiply the price by the tax rate to get the tax owed, then add that to the price for the total you actually pay.

Working backward — from a receipt total to the pre-tax price — is not the same as subtracting the tax rate from the total. The rate applies to the pre-tax price, not to the total, so the correct method divides the total by (1 + rate) to recover the pre-tax price first, then finds the tax as the difference.

Rates are set locally, not centrally
In the US, sales tax is set by the state and often layered with county, city and special-district rates. There is no single national rate — enter the combined rate for your specific location.
Not every item is taxed the same
Groceries, medication and sometimes clothing are commonly taxed at a reduced rate or exempt entirely, while prepared food and some services can carry extra rates. This tool applies one flat rate to the whole amount you enter.

The formulas

tax = price × (rate ÷ 100)  ·  total = price + tax

Reversed: price = total ÷ (1 + rate ÷ 100)  ·  tax = total − price

Worked example

An $80.00 item at an 8.25% combined rate: tax = 80 × 0.0825 = $6.60, for a total of $86.60. Going the other way, an $86.60 receipt total at the same 8.25% rate divides back to price = 86.60 ÷ 1.0825 = $80.00, with $6.60 of that total being tax.

Frequently asked questions

How is sales tax calculated?
Sales tax is a percentage of the pre-tax price, added on top: tax = price × (rate ÷ 100), and the total you pay is price + tax. A $80 item at an 8.25% combined rate has $6.60 of tax, for a total of $86.60.
How do I find the pre-tax price from a total I already paid?
Divide the tax-included total by (1 + rate ÷ 100) rather than simply subtracting the rate — the rate applies to the pre-tax price, not to the total, so subtracting it directly overstates the pre-tax price. A $86.60 total at 8.25% divides back to an $80.00 pre-tax price, not $86.60 − 8.25% of $86.60.
Why do sales tax rates vary so much by location?
In the US, sales tax is set at the state level and often layered with county, city and special-district rates on top, so the "combined" rate can differ block to block within the same state. Some states charge no general sales tax at all. Look up the exact combined rate for a specific address through your state's department of revenue rather than relying on a state-average figure.
Are all purchases taxed at the same rate?
No. Many jurisdictions tax groceries, prescription medication, and sometimes clothing at a reduced rate or exempt them entirely, while other categories (prepared food, alcohol, some services) can carry an additional rate on top of the general one. This calculator applies a single flat rate you provide; check your item's category with your local taxing authority for an exact figure.
Sources and method
  • Sales tax formula and mechanics — general published US state and local tax law; each state's department of revenue publishes its own current rates and exemption rules.
  • State sales tax rates vary and are set independently by each jurisdiction — see the Tax Foundation's published state sales tax rate research for a general comparison, or your state's department of revenue for an exact figure.
Last reviewed: 19 Sep 2026 Sources last verified: 19 Sep 2026 Results use the assumptions explained on this page. Report an error How we check calculations

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