Sales Tax Calculator
Add or reverse-calculate sales tax on any purchase amount.
Result
How to Use This Calculator
Choose whether the amount you have is pre-tax or already includes tax, enter the amount and the applicable sales tax rate, and see the breakdown instantly.
How the Calculation Works
Adding tax multiplies the pre-tax amount by the tax rate. Reverse-calculating from a final price divides it out instead.
Formula
Tax = Pre-tax Amount × (Rate / 100)
Pre-tax Amount = Final Price / (1 + Rate / 100), when working backward from a final price
Example Calculation
A $100 pre-tax purchase at a 7% rate has $7.00 in tax, for a $107.00 final price.
Frequently Asked Questions
Is a rate I enter guaranteed to be current?
No — sales tax rates change and vary by exact location. Confirm the applicable rate with your local jurisdiction or point of sale.
Related Tools
Disclaimer
Sales Tax Calculator: Add It or Reverse It in Seconds
"Sales tax calculator" is a simple search, but an extremely common one, because sales tax rates change constantly by state, county, and sometimes even by city — there's no single number that applies everywhere in the U.S. This tool handles the two directions people actually need: adding tax to a pre-tax price, or working backward from a final receipt total to figure out what the item cost before tax.
The forward direction covers the classic "calculate sales tax" use case — you know a listed price and your local rate, and you want the final total before you check out. The reverse direction, often searched as "reverse sales tax calculator" or "price before tax calculator," is just as commonly needed: you have a receipt or a final charged amount and want to know the pre-tax price, whether for expense reporting, budgeting, or simply curiosity about how much of a purchase was tax versus the item itself.
Because rates genuinely vary by location — and change over time as local governments adjust them — this calculator deliberately doesn't try to guess or auto-fill a rate based on "sales tax calculator by state" lookups. Instead, you enter the exact rate that applies to your purchase, which keeps the math accurate rather than approximate. If you're not sure of your local combined state-plus-county-plus-city rate, your state's department of revenue website is the most reliable source, and many receipts show the effective rate directly if you divide the tax charged by the pre-tax subtotal.
This tool is intentionally minimal because the underlying math is simple, but that simplicity is exactly why it gets used so often — for checking a big-ticket purchase like electronics or furniture before you buy, for splitting a shared purchase where sales tax needs to be divided fairly, or for reconciling a business expense report where you need the pre-tax amount for accounting purposes. Pair it with the Tip Calculator if you're trying to work out a full restaurant bill, since tax and tip are usually calculated on different base amounts and it's easy to accidentally tip on top of tax by mistake.
Online shoppers also use a "sales tax calculator" like this one to compare the real, final cost of an item across different shipping addresses or store locations before checking out, since displayed prices don't always include tax until the final step. Running the numbers here first avoids surprises at checkout and makes it easier to compare two similarly priced listings on an apples-to-apples, tax-included basis.