What the calculator shows
Enter an amount, choose whether it is before tax or the final total, and enter the combined rate for the purchase location. The 7.5% starting value is a rounded planning reference based on the 2026 state and local rate landscape.
Calculation method
For a pre-tax amount, tax equals price × rate and total equals price plus tax. For a tax-inclusive total, pre-tax price equals total ÷ (1 + rate) and tax is the difference.
Inputs to confirm
Use the rate for the delivery or purchase jurisdiction and confirm whether the item or service is taxable. Grocery, clothing, digital products, vehicles and business purchases can follow special state and local rules.
Worked add-and-reverse example
At a 7.5% combined rate, $100 before tax produces $7.50 tax and a $107.50 total. Entering $107.50 as tax included recovers the same $100 base because reverse mode divides by 1.075.
| Entered amount | Meaning | Result at 7.5% |
|---|---|---|
| $100 | Before tax | $107.50 total |
| $107.50 | Tax included | $100 base + $7.50 tax |
| $100 | Tax-exempt amount | Do not apply the calculator rate |
The arithmetic is simple; choosing the correct rate and tax base is not
The calculator can add tax or extract the tax contained in a total, but it cannot decide which state and local jurisdictions apply or whether the product is taxable.
Combined rates can include several layers
A checkout rate may combine state, county, city and special-district components. Use the rate for the transaction location and date rather than the national planning reference. Online sales and delivered goods may follow sourcing rules that differ from the seller’s address.
Taxability depends on the item and transaction
Food, clothing, services, digital products, holidays, exemptions and vehicles can receive special treatment. Enter only the taxable amount and applicable combined rate after checking the jurisdiction or receipt.
Reverse calculation explains a tax-included total
When the total already includes tax, dividing by one plus the rate finds the implied before-tax amount. Multiplying the total by the rate would overstate tax because the total already contains both price and tax.
| Input | Question to answer | Evidence |
|---|---|---|
| Amount | Which part is taxable? | Invoice or product rule |
| Combined rate | Which jurisdictions apply? | State or local lookup |
| Amount meaning | Before tax or tax included? | Receipt or quoted total |