Sales Tax Calculator

How to use the sales tax calculator

Enter an amount, your combined sales tax rate, and pick a mode. In Add tax mode — the default — the amount is your pre-tax price and the tool returns the tax and the all-in total. In Remove tax mode the amount is a tax-inclusive total and the tool works backward to the pre-tax price. The rate field defaults to 7.25%, but that’s just a placeholder: there’s no single right number, so enter the one that applies where you are.

There is no federal sales tax in the United States. Rates are set by states and by local jurisdictions — counties, cities, and special districts — and they stack, so your “combined” rate is the state rate plus every local rate that applies at the point of sale. The spread is wide: a handful of states have no statewide sales tax at all (an effective 0%), while some cities push the combined rate up toward 10%. Two addresses in the same state can owe different amounts, which is why this tool asks you to type in your own combined rate rather than guessing one for you.

US prices are almost always shown tax-exclusive: the shelf or menu price is the pre-tax amount, and tax is added at the register. That’s what Add tax mode mirrors — you know the sticker price and want to see what you’ll actually hand over. It’s handy for budgeting a purchase, checking a quote, or sanity-checking a receipt line by line before you pay.

Much of the world prices the other way. In many countries a value-added tax (VAT) or goods-and-services tax (GST) is already baked into the displayed price — tax-inclusive — so the number on the tag is the number you pay. Remove tax mode is built for that situation and for the reverse problem at home: you have an all-in total and need the pre-tax figure underneath it.

That remove-tax case comes up constantly with expense reports and bookkeeping. When all you have is a receipt’s grand total and the tax rate, this tool backs the tax out and recovers the pre-tax amount and the tax portion separately — exactly what you need to log a net expense or reclaim tax. Switch modes anytime; the math simply runs in the opposite direction.

The formula

Convert the rate to a decimal first (rate = tax% ÷ 100), then the two modes are inverses of each other — one adds tax on, the other strips it out:

rate = tax% ÷ 100
add tax     →  tax = amount × rate,  total = amount + tax
remove tax  →  pre-tax = amount ÷ (1 + rate),  tax = amount − pre-tax

Worked example with the defaults — $100.00 at 7.25%. Add tax: 100.00 × 0.0725 = $7.25 in tax, for a $107.25 total. Removing tax is the exact reverse: take that $107.25 at 7.25% and divide by 1.0725 to get $100.00 back as the pre-tax amount, leaving $7.25 as tax. The two modes are mirror images, so what one adds the other recovers down to the cent.

The same math scales to any rate. At a round 10%, a $50.00 pre-tax amount adds $5.00 of tax for a $55.00 total. Removing tax is not the same as subtracting the rate: 7.25% of a tax-inclusive total is more than the tax it contains, which is why backing it out divides by 1 + rate instead.

Frequently asked questions

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