Unlike VAT in Europe, US sales tax is added at checkout, not baked into shelf prices. That's why your $19.99 t-shirt rings up at $21.64 in one state and $19.99 in another. This guide explains the sales tax formula, how rates vary across the US, and how to use a free sales tax calculator to avoid budget surprises.
What is sales tax?
Sales tax is a consumption tax charged on the sale of goods and certain services. In the US, it's collected by the retailer and remitted to the state and (often) local jurisdictions. There is no federal sales tax — every rate is set at the state, county or city level.
The sales tax formula
Tax = Pre-tax price × (Tax rate ÷ 100). Total = Pre-tax price + Tax. That's the whole math.
Example: a $100 item in a state with 8.25% sales tax = $100 × 0.0825 = $8.25 tax. Total = $108.25.
Worked examples
- $45 dinner in Texas (8.25% combined): tax = $3.71, total = $48.71
- $1,200 laptop in California (avg 8.85%): tax = $106.20, total = $1,306.20
- $25 book in New York City (8.875%): tax = $2.22, total = $27.22
- $80 jeans in Oregon (0% sales tax): tax = $0, total = $80
Sales tax by US state — what to expect
Five states have no statewide sales tax: Alaska, Delaware, Montana, New Hampshire and Oregon. The other 45 states plus DC charge between 4% (Hawaii) and around 7.25% (California) at the state level, with local add-ons pushing combined rates above 10% in some cities.
Combined rates change frequently — always confirm with the retailer or your state's revenue department for big purchases.
Common exemptions
- Groceries are tax-exempt or reduced in most states
- Prescription medications are usually exempt
- Clothing under a price threshold is exempt in some states (e.g. New York under $110)
- Resale items purchased with a valid resale certificate are exempt
Use our free sales tax calculator
Enter the pre-tax price and the tax rate — SnapFetch's free sales tax calculator returns the tax amount and the final total instantly. Useful for invoices, budgeting and quick checkout sanity checks.
Try our free sales tax calculator before your next big purchase.
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