Understanding the sales tax calculator
U.S. sales tax is added at the register rather than shown in the shelf price, and the rate is a stack: a state rate plus optional county, city, and special-district rates. Combined rates range from zero in a handful of states to over 10% in some cities, and what is taxable (groceries, clothing, services) varies just as widely.
The reverse calculation trips people up: a $108.25 receipt at 8.25% is not $108.25 minus 8.25%. The tax was applied to the smaller pre-tax amount, so you divide by 1.0825 instead the third result row does this for you, which is handy for expense reports and bookkeeping.
Results are estimates for education only and are not financial advice.