How do I calculate sales tax on a price?

Multiply the pre-tax price by the tax rate (as a decimal) to get the tax amount, then add it to the price for the total: total = price + (price × rate). For example, a $100 item at 7.25% tax adds $7.25 in tax for a $107.25 total. Use "Add tax to a price" mode and this happens automatically.

How do I work backward from a total that already includes tax?

Divide the tax-included total by (1 + the tax rate as a decimal) to get the pre-tax price: price = total ÷ (1 + rate). A $107.25 total at 7.25% tax works out to a $100.00 pre-tax price. Use "Remove tax from a total" mode — this is the calculation most receipts and invoices don't show you directly.

Why can't I just subtract the tax rate percentage from the total?

Because the tax rate applies to the pre-tax price, not the total — subtracting 7.25% directly from a $107.25 total gives $99.48, not the correct $100.00 pre-tax price. This is the same reverse-percentage mistake people make with tips and discounts; dividing by (1 + rate) is the correct way to undo a percentage that was added on.

How accurate are the state tax rates in the calculator?

They're representative averages — a state's statewide base rate, and a typical "combined" rate that adds an average local add-on. Real combined rates vary by exact city, county, and special tax district, and change over time as legislatures and localities adjust them. Treat the auto-filled rate as a starting point, then edit it directly if you know your exact local rate.

Which states have no sales tax?

Alaska, Delaware, Montana, New Hampshire, and Oregon have no statewide sales tax. Alaska is the exception among these — many of its localities still levy their own local sales tax, so a purchase there can still carry tax even without a state-level rate.

Why do combined rates vary so much between states?

Some states rely mostly on a single statewide rate with little local add-on (like Massachusetts or Kentucky), while others set a lower state rate and let cities, counties, and special districts stack their own tax on top (like Colorado or Louisiana) — two states with similar statewide rates can end up with very different real-world combined rates.

Does this calculator handle exemptions or special tax categories?

No — many states exempt or reduce tax on categories like groceries, prescription drugs, or clothing under a certain price. This calculator applies one flat rate to the full amount you enter, so for exempt or partially-exempt purchases, apply the rate only to the taxable portion yourself.

AI Insights

Sales Tax Calculator

Add or reverse-calculate sales tax on any price — enter a rate directly or start from a U.S. state to auto-fill a representative rate.

Last updated August 16, 2026

Price before tax

Tax rate

Rate (%)

Total with tax

$107.25

Tax: $7.25 at 7.25%

Line item	Amount
Price before tax	$100.00
Sales tax (7.25%)	$7.25
Total	$107.25

When buying items in this price range, a quick comparison between nearby towns can sometimes reveal enough of a rate difference to offset the cost of gas. Keeping your receipt in a safe place is also extra important here, as it makes returns, exchanges, or warranty claims much smoother if something goes wrong.

AI-generated insight

State rates are representative averages for quick estimates, not exact real-time local rates — verify the precise rate for your address with your state department of revenue before filing or pricing.

How to use the sales tax calculator

1
Choose "Add tax" if you have a pre-tax price, or "Remove tax" if you already have a tax-included total.
2
Enter the amount — the label changes automatically to match the direction you picked.
3
Set the tax rate — type it manually, tap a common preset, or switch to "By state" to auto-fill a representative rate you can still edit.
4
Your pre-tax price, tax amount, and total update instantly as you adjust any field.

How adding and removing tax works

The same rate works forward (price → total) or backward (total → price) — just don't subtract the rate directly from the total.

Adding tax is straightforward multiplication: total = price × (1 + rate). Removing tax from a total that already includes it requires division, not subtraction, because the rate was applied to the smaller pre-tax price, not the total: price = total ÷ (1 + rate).

Worked example: a $214.50 total that already includes 7.25% tax. Dividing by 1.0725 gives a pre-tax price of $200.00, meaning $14.50 of that total was tax — not the $15.55 you'd get by (incorrectly) multiplying $214.50 by 7.25% directly.

State and local rates explained

Most U.S. sales tax is really two layers stacked together: a statewide base rate set by the state legislature, plus local add-ons from cities, counties, and special taxing districts that can vary block to block. The "By state" option gives you both the state-only rate and a representative combined average — a useful starting point, but not a substitute for the exact rate at a specific address, which can shift by a full percentage point or more between two nearby ZIP codes.

Alaska, Delaware, Montana, New Hampshire, and Oregon have no statewide sales tax — though Alaska still allows local sales tax in many municipalities, so "no state tax" doesn't always mean "no tax at all."

Splitting a tax-included restaurant bill? Our Tip Calculator handles the tip math once you know the tax-free subtotal.

Need a different percentage calculation — discounts, percent change, or finding a whole from a part? Try the Percentage Calculator →

Frequently asked questions

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