Sales Tax Calculator
Add sales tax to a price, or back it out of a tax-included total. It runs entirely in your browser, so the file never leaves your computer.
Both directions, which is the useful part
Adding tax to a price is easy enough to do in your head. Backing it out of a total is the one people reach for a calculator for, and it is the one most quick tools skip.
You have a receipt showing $64.79 including tax and you need the pre-tax figure for an expense claim. That is not subtracting the tax rate — it is dividing by one plus the rate, which is why doing it the obvious way gives the wrong answer. This does it correctly in both directions.
The rate is yours to supply
This does not look up your rate, because US sales tax is set at state, county and city level and the combined figure can differ between two addresses a mile apart.
Use your local combined rate, or read it off a recent receipt, which is the most reliable source you have.
Why the total may differ by a cent
The arithmetic here is exact for the rate you give it. A real receipt can still come out a penny or two different, because many systems calculate and round tax per line item rather than once on the total, and some items are exempt.
Treat the result as a close estimate rather than a prediction of what the register will print.
Questions
Common questions
What does this tool do?
It adds sales tax to a price to get the total, or works backward from a tax-included total to find the original pre-tax price. Enter your local tax rate and the amount.
How do I add tax to a price?
Use 'Add tax' mode, enter the pre-tax price and your tax rate, and it shows the tax amount and the final total.
How do I find the price before tax?
Use 'Remove tax (back out)' mode and enter a total that already includes tax. It calculates the original pre-tax price and how much of the total was tax — handy for receipts that only show the final amount.
What tax rate should I use?
Enter the combined sales tax rate that applies where you are. Rates vary by state, county, and city, so check your local rate or a recent receipt — this tool doesn't look it up for you.
Is this accurate for my purchase?
The math is exact for the rate you enter, but real receipts can differ slightly because of rounding per item or tax-exempt items. Treat it as a close estimate.
Is it private?
Yes. Everything is calculated in your browser — no ads, nothing uploaded.
Our own software
Dictate it instead of typing it
Hold a key, say the sentence, and the words land in whatever Windows window you were already in. Runs on your own PC — no account, no upload, nothing to renew.
$79 launch price · $99 regular · buy once