Sales Tax Calculator — Use a Rate You Know
Add sales tax to a price, back tax out of a total that already includes it, or total a few line items you mark as taxable.
Enter a sales tax rate you already know. This tool calculates amounts; it does not find the right rate or decide what is taxable.
Sales tax estimate
How it was calculated
Because tax is rounded to the cent, adding tax back to gives of tax, not .
This is an estimate based on the rate and choices you entered. Rates, what's taxable, rounding and seller practices vary by state and locality; check with your state tax agency or the seller. Find your state tax agency.
Amounts, rates and line choices stay in this browser tab; copying or downloading is your choice.
In Canada? GST/HST Calculator (Canada) · In Australia? GST Calculator (Australia)
Three ways to use the calculator
Add tax: a $100.00 price at 8.25% gives $8.25 of tax and a $108.25 total.
Remove tax from total (reverse sales tax): a $108.25 total that already includes 8.25% tax splits into a $100.00 pre-tax amount and $8.25 of tax.
Itemized estimate: a $100.00 item you include and a $50.00 item you don't include, at 8.25%, give a $150.00 subtotal, a $100.00 taxable base, $8.25 of tax and a $158.25 total.
How the math and rounding work
Tax is the taxable amount times the rate, rounded to the nearest cent with half a cent rounded up. In itemized mode the calculator adds up the lines you marked as included first and rounds the tax once on that total, rather than rounding each line. The calculations use whole cents, so there are no floating-point surprises such as $8.249999.
Finding the right rate is a separate step
Sales tax in the US is set by states and often by counties, cities and special districts too, so the right rate can depend on the exact address and date. It can also depend on what is being sold. This calculator doesn't look up rates or decide what is taxable — enter a rate you know, and check it with your state's tax agency or the seller when it matters. The links below go to official rate pages for a few states.
What this calculator is not
It gives an estimate from the rate and choices you enter. It is not tax or legal advice, a rate certification, a filing amount or a receipt that must match the store's. Discounts, shipping, coupons, returns and items taxed at different rates are not handled.
Privacy
Amounts, rates and line choices stay in this browser tab; copying or downloading is your choice. Site analytics count only actions such as calculating or copying, never the amounts, the rate or your labels.
Frequently asked questions
Where do I find a sales tax rate?
Use your state's official tax agency lookup, a receipt or quote from the seller, or your business's tax records. Rates can depend on the exact address and date, so a single state-wide number may not be right. This calculator uses whatever rate you enter and does not look one up.
Does this decide whether an item is taxable?
No. In itemized mode you choose, line by line, whether each amount goes into the taxable base. The calculator doesn't know your state's rules about groceries, clothing, services or other items, so check them with your tax authority or the seller.
Why can a receipt differ by a cent?
Sales tax is rounded to whole cents, and sellers may round per item, per line or on the whole order. This calculator rounds once, to the nearest cent with half a cent rounded up, on the pre-tax amount or on the taxable base you marked. A store that rounds differently can end up a cent apart.
How is tax backed out of a total?
In "Remove tax from total" mode the calculator divides the total by 1 plus the rate (for 8.25%, by 1.0825) to find the pre-tax amount, rounds it to the cent, and treats the rest as tax. Because of cent rounding, adding tax back to that pre-tax amount can occasionally give a total one cent different; the result says so when that happens.
Are my amounts uploaded?
No. Amounts, rates, labels and line choices stay in this browser tab. They are not put in the page address, saved in the browser or sent in analytics. Copying or downloading a summary is your choice.