What you pay after the discount
To take a percentage off a price, multiply by the share that remains: Final price = original price × (1 − percent off ÷ 100). For 30% off $120, you keep 70% of the price: 120 × 0.70 = $84, saving $36. The amount saved is original price minus final price.
How to use this calculator
Enter the original price and the percent off from the tag or ad. The result shows the final price and the dollar amount you save, updating instantly so you can compare offers while you shop. Tax goes on afterwards, which the sales tax calculator adds.
The fast mental-math trick
To estimate any percent off in your head, start with 10%: just move the decimal one place left. 10% of $120 is $12, so 30% is 3 × $12 = $36 off → $84. For 15%, take 10% plus half of it. For 25%, a quarter — divide by four. These shortcuts get you close without a calculator. Comparing pack sizes on sale is a job for the unit price calculator.
Percent-off quick reference
For a $120 item:
| Percent off | You save | You pay |
|---|---|---|
| 10% | $12.00 | $108.00 |
| 20% | $24.00 | $96.00 |
| 30% | $36.00 | $84.00 |
| 40% | $48.00 | $72.00 |
| 50% | $60.00 | $60.00 |
Extra percent off and sales tax
An additional percent off applies to the already-reduced price, not the original — so 30% then an extra 10% is 37% off in total, not 40%. Sales tax is added afterward on the discounted price. For the same math framed as a sale price, see the discount calculator; sellers can check what a markdown costs them with the margin calculator.
These figures are an estimate for general information only and are not financial advice; consult a qualified professional before making money decisions.
Frequently asked questions
- How do I calculate percent off a price?
- Multiply the price by the percent as a decimal to get the savings, then subtract. For 30% off $120: 120 × 0.30 = $36 saved, so you pay $84. Or multiply by 0.70 directly to get $84.
- What is 30% off $120?
- $36 off, leaving a final price of $84.
- How do I do percent off in my head?
- Find 10% by moving the decimal one place left, then scale it. 10% of $120 is $12, so 30% is $36 off.
- Does an extra percent off add to the first?
- No. The second discount applies to the reduced price, so 30% then an extra 10% off equals 37% off in total, not 40%.
- Is tax added before or after the discount?
- After. Sales tax is calculated on the discounted price, so the percent off is applied first.