Sales tax is added at the register, so the shelf price is rarely what you actually pay. This calculator adds tax to any price, or works backward from a receipt to tell you what rate you were charged. If you need the tax rate for a particular state, use the state sales tax calculator, which has every state’s rate built in.
How to use the sales tax calculator
- Choose Tax and total to add tax to a price, or Tax rate paid to find the rate from a receipt.
- Enter the price before tax. For several identical items, enter the quantity too.
- Enter the combined sales tax rate (state plus local), or, in rate mode, the total you paid.
- Read the total on the tape, with the tax amount and a table of the same purchase at other common rates.
Sales tax formulas
The calculator rounds the tax to the nearest cent, as stores do, and shows the exact unrounded figure when the two differ.
Worked examples
Adding tax. A $100.00 purchase at 7.25%: tax = 100 × 0.0725 = $7.25; total = $107.25.
Several items. Three items at $24.99 at 8.25%: subtotal = $74.97; tax = 74.97 × 0.0825 = $6.185 → $6.19; total = $81.16.
Finding the rate. A receipt shows $100.00 before tax and $108.25 total: tax = $8.25; rate = 8.25 ÷ 100 = 8.25%.
Sales tax on $100 at common rates
| Rate | Tax | Total |
|---|---|---|
| 4% | $4.00 | $104.00 |
| 6% | $6.00 | $106.00 |
| 6.25% | $6.25 | $106.25 |
| 7% | $7.00 | $107.00 |
| 8.25% | $8.25 | $108.25 |
| 8.875% | $8.88 | $108.88 |
| 9.5% | $9.50 | $109.50 |
Because tax is a percentage, scaling is easy: tax on $250 is two and a half times the tax on $100.
Things that change the tax you pay
What is taxable
States differ on what they tax. Many exempt or reduce the rate on groceries and prescription drugs; some tax clothing only above a price threshold; services such as haircuts or repairs are taxed in some states and not others. A single receipt can mix taxable and exempt items, so the overall rate may look lower than the posted rate.
Discounts and coupons
A store discount is usually taken before tax, so you pay tax on the reduced price. Manufacturer coupons are treated differently in some states, where tax is charged on the pre-coupon price. The discount calculator applies a discount and then tax in the usual order.
Shipping and fees
Some states tax delivery charges when they are part of the sale; others exempt separately stated shipping. The sales calculator lets you choose whether shipping is taxable.
Working backward from a total
If you only know the tax-inclusive total, don’t multiply the total by the rate — that overstates the tax. Divide instead: the reverse sales tax calculator does it in one step.
Results are estimates. Taxability and local rates vary; your state revenue department publishes the official rules.
Frequently asked questions
How do I calculate sales tax?
Convert the rate to a decimal and multiply by the pre-tax price. At 7.25%, tax on $100 is 100 × 0.0725 = $7.25, so the total is $107.25. You can also multiply the price by 1.0725 to get the total in one step.
How do I find the sales tax rate from a receipt?
Subtract the pre-tax price from the total to get the tax, then divide the tax by the pre-tax price. A $100 item that cost $108.25 in total carried $8.25 of tax, which is 8.25%.
Is sales tax rounded up?
Most states round to the nearest cent, with half a cent rounding up. Retailers usually calculate tax on the whole invoice rather than item by item, which can make the total differ by a cent from adding up individually taxed items.
Is there a federal sales tax in the US?
No. Sales tax is set by states and local governments. Forty-five states and Washington, DC levy a statewide sales tax, and many cities, counties and districts add their own rates on top.