Sales Tax Calculator
Fill in any two of before-tax price, sales tax rate and after-tax price, and the third one is worked out.
Example
Sample: $100 before tax at a 6.5% rate.
This is a sample result, not your calculation. Enter your own values to replace it.
Enter any two of the three, then calculate.
After Tax Price
All three
- Before Tax Price
- —
- Sales Tax
- —
- After Tax Price
- —
Check your entries
How to use this calculator
- Fill in any two of the three: before-tax price, sales tax rate, after-tax price.
- Leave the third one blank — that is the one worked out.
- Press Calculate to see all three figures together, with the tax on its own line as both a percentage and an amount.
There is no mode to choose. The blank box is the mode, which means the tool can never be set to one thing while you are typing another.
The three questions this answers
They are one equation — after = before × (1 + rate) — read three ways.
- What will this cost at the till? Leave After Tax Price blank. $100 at 6.5% adds $6.50, so you pay $106.50.
- What was the price before tax? Leave Before Tax Price blank. $106.50 ÷ 1.065 = $100.00.
- What rate was I charged? Leave Sales Tax Rate blank. ($106.50 − $100.00) ÷ $100.00 = 6.5%.
The mistake worth avoiding
To go from a tax-inclusive total back to the price before tax, you divide by 1 + the rate. You do not subtract the rate. Taking 6.5% off $106.50 gives $99.58, which is wrong by 42 cents, because that 6.5% was a percentage of the smaller number to begin with. The gap grows with the rate: at 20%, the same mistake on a $120 receipt gives $96 instead of $100 — out by $4.
Where the rate comes from
The United States has no national sales tax. Each state sets its own, and counties and cities add theirs on top, so what you pay is a combined rate that can differ between two shops a few miles apart. Rates also vary by what you are buying — groceries, prescriptions and clothing are treated differently from state to state.
Five states levy no statewide sales tax: Alaska, Delaware, Montana, New Hampshire and Oregon. Alaska is the one to watch, because its boroughs can still charge their own.
Sales tax is not VAT
Sales tax is charged once, at the final sale to the consumer. VAT is collected in stages along the supply chain, with each business reclaiming the tax it paid, and it is normally quoted inside the shelf price rather than added at the till. The arithmetic here works for either — a VAT-inclusive price is just an after-tax price — but the two systems are not interchangeable.
To work a rate into a bigger purchase, the auto loan calculator applies state sales tax to a vehicle price. These figures are for general use, not tax advice.
Read more
- How to Calculate Sales Tax Add sales tax to a price or back it out of a total, understand how rates work, and avoid the rounding mistakes that trip up expense reports.
- How VAT Works: Adding It, Removing It, and Getting It Right Add VAT to a net price, strip it back out of a gross one, and understand why you divide rather than subtract — with the rate rules that catch people out.
Frequently asked questions
How do I calculate sales tax?
Multiply the before-tax price by the rate as a decimal to get the tax, then add it on. $100 at 6.5% is $6.50 of tax and $106.50 at the till. Leave the After Tax Price blank here and the calculator does exactly that.
How do I work out the price before tax?
Divide the total by one plus the rate — not by subtracting the rate, which is the common mistake. $106.50 at 6.5% is 106.50 ÷ 1.065 = $100.00, whereas taking 6.5% off $106.50 would wrongly give $99.58. Leave Before Tax Price blank and the calculator divides for you.
How do I find the tax rate from two prices?
Subtract to get the tax, then divide by the before-tax price: ($106.50 − $100.00) ÷ $100.00 = 6.5%. Leave Sales Tax Rate blank and enter the other two. This is the quickest way to read the rate off a receipt.
What is sales tax?
A percentage added at the point of sale, collected by the seller and passed to the government. The United States has no national sales tax — it is set by state and local jurisdictions, so the combined rate depends on where the sale happens and can differ between two shops a few miles apart.
Which states have no sales tax?
Five have no statewide sales tax: Alaska, Delaware, Montana, New Hampshire and Oregon. Alaska is the exception that matters — local boroughs there can and do levy their own, so "no sales tax" is only true statewide.
Is sales tax the same as VAT?
No. Sales tax is charged once, at the final sale to the consumer. VAT is collected in stages along the supply chain, with each business reclaiming what it paid, and is usually quoted inside the shelf price rather than added at the till.
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About this calculator
Method reviewed for accuracy on July 18, 2026
Built on transparent, unit-tested formulas that run entirely in your browser — see how we build our calculators.
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