US Sales Tax Calculator

What this calculator does. It works in both directions: enter a pre-tax price and a combined sales tax rate to get the total, or enter a tax-inclusive total to back out the pre-tax price and the tax portion. It's useful for budgeting purchases, checking receipts, preparing expense claims and pricing goods for sale.

How the calculation works. Sales tax is a simple percentage of the pre-tax price. To add tax, multiply the net price by (1 + rate). To remove tax from a total, divide by (1 + rate) to recover the pre-tax price, then subtract that from the total to find the tax. The same arithmetic works at any rate, so it's safe to use whether your local combined rate is 4% or 11%.

A worked example. A laptop listed at $1,200 in a city with a combined 8.25% sales tax rate. Adding tax: $1,200 × 1.0825 = $1,299 total, with $99 of that being tax. Working backwards from a $1,299 receipt at the same rate: $1,299 ÷ 1.0825 = $1,200 pre-tax, confirming $99 in sales tax. Switch the rate to 4% (Hawaii's general excise tax for comparison) and the same $1,200 item totals $1,248 — a $51 difference on one purchase.

Why this matters. US sales tax is genuinely local — the same product can cost noticeably more or less depending on where you buy it, and online orders are taxed at the delivery address. Knowing the real after-tax price makes it easier to compare quotes, decide whether a cross-state purchase is worth the trip, claim back the right amount on expenses, and avoid quietly busting a budget at the till.

When to use it / when not to. Use it for any standard retail transaction in the US. For VAT in the UK or EU, use our VAT calculator instead — the maths is similar but the rates, exemptions and invoicing rules are different. For sales of cars, alcohol, fuel and tobacco, additional excise taxes often apply on top of sales tax and aren't included here.

Common mistakes. Using only the state rate and forgetting county or city add-ons (often the bigger chunk in places like Chicago or Los Angeles); applying sales tax to grocery or prescription purchases where many states exempt or reduce the rate; and confusing tax-inclusive ("VAT-style") European prices with US-style pre-tax shelf prices — at a US till, the displayed price almost always excludes tax.