Use the combined state and local rate for where the item is delivered; online sellers charge the rate at the delivery address.
Tax at common rates
How it works
Tax = price × rate; total = price × (1 + rate). From a total that includes tax, the pre-tax price = total ÷ (1 + rate).
Shopping around? Shopping list total finds the cheapest price for each thing you need.
Questions
How do I add sales tax to a price?
Multiply the price by one plus the tax rate. A $100 item at 7% tax costs 100 × 1.07 = $107.
How do I take sales tax out of a total?
Divide the total by one plus the rate. A $107 receipt at 7% tax was $100 before tax, with $7 of tax. Taking 7% off $107 gives $99.51, which is wrong.
Which sales tax rate applies when I shop online?
Online sellers charge the combined state and local rate at the delivery address, not where the seller is. Five states have no statewide sales tax: Alaska, Delaware, Montana, New Hampshire and Oregon, though some Alaska towns add their own.
Is shipping taxed?
In many states shipping is taxable when the item is, and in others it is exempt if listed separately. Check your state's rules if the amount matters.