How U.S. sales tax works
Forty-five states and Washington, D.C. levy a statewide sales tax, and in 38 states local governments add their own on top. The combined rate you pay at the register is the state base rate plus any county, city, and special-district rates — which is why the same purchase can be taxed at 6% in one ZIP code and over 10% a few miles away. Five states — Alaska, Delaware, Montana, New Hampshire, and Oregon — have no statewide sales tax at all (though some Alaska localities levy their own).
State base rates at a glance (2026)
The highest statutory state rates are California (7.25%), Indiana, Mississippi, Rhode Island, and Tennessee (7%). The lowest non-zero rate is Colorado at 2.9% — though Colorado's local additions are among the nation's largest. When the calculator fills in your state's rate, remember it's the base: groceries, clothing, and medicine are fully or partially exempt in many states, and local rates commonly add 1–5 percentage points.
Reverse sales tax: pulling the tax out of a total
Got a receipt total and need the pre-tax price — for expense reports, bookkeeping, or invoicing? You can't just subtract the percentage. The correct formula divides instead: pre-tax price = total ÷ (1 + rate). A $107.25 total at 7.25% is $100.00 before tax, not $99.47. Choose "Remove tax" mode above and the division is done for you.
Online purchases and use tax
Since the Supreme Court's Wayfair decision (2018), large online retailers must collect sales tax based on your delivery address in states that require it. If a seller doesn't collect, most states technically require you to self-report "use tax" on your state return for taxable purchases — a rule that matters mainly for businesses buying equipment from out of state.