Discount calculator
Enter the price and discount, get the sale price and savings instantly.
How do I calculate a discount?
Multiply the price by the percent off and subtract. 25% off $80 is 80 × 0.25 = $20 off, so you pay $60. Or multiply by what is left: 80 × 0.75 = $60.
Is 20% off plus an extra 10% off the same as 30% off?
No. The extra 10% comes off the already reduced price: $100 minus 20% is $80, and 10% off $80 is $72 — a total of 28% off, not 30%.
How do I find the original price from the sale price?
Divide the sale price by what is left after the discount. If $60 is 25% off, the original price was 60 ÷ 0.75 = $80.
Is sales tax charged on the original price or the sale price?
In most states, on the price you actually pay after store discounts. Manufacturer coupons can be treated differently from store coupons; enter your tax rate and the calculator applies it to the sale price.
What is 30% off $45?
$13.50 off, so $31.50. The table under the result shows your price at 10% to 50% off.
What happens if I take 50% off and then another 50% off?
You pay 25% of the original price, not nothing: the second 50% applies to the already halved price. $100 becomes $25.00, a saving of 75%. In general two discounts of a% and b% combine to 1 − (1 − a)(1 − b).
If an item is 20% off, what percent increase would restore the old price?
25%, not 20%. The sale price is 80% of the original, and getting from 80 back to 100 means adding a quarter of 80. The same asymmetry explains why a price cut followed by an equal percent rise ends lower than where it started.
The formulas
A single discount: sale price = original × (1 − discount ÷ 100), and savings = original − sale price. A second discount applied to the sale price multiplies in a second factor: sale = original × (1 − a ÷ 100) × (1 − b ÷ 100). The total percent off is then (original − sale) ÷ original, which is always less than a + b. Tax, if you enter it, is added to the final sale price, which is how most US sellers compute it when the discount is a store markdown.
Worked example: 30% off plus an extra 15%, with tax
Take a $120 jacket marked 30% off with an extra 15% off at the register. The first step leaves $120 × 0.70 = $84.00; the second leaves $84.00 × 0.85 = $71.40. You save $48.60, which is 40.50% off, not 45%. With 8% sales tax the total is $77.11. A simple 25% discount on $80, for comparison, leaves $60.00 and saves $20.00.
Common mistakes
Adding two percentages (30% + 15%) overstates the saving; always apply them one after the other. Percent off is relative to the price you start from, so the same “$10 off” is a larger percentage of a cheap item. Another trap is the reference price: under the Federal Trade Commission’s Guides Against Deceptive Pricing (16 CFR 233.1), a “former price” used for a comparison should be a price at which the item was actually offered for a reasonably substantial period, so a big markdown from a rarely used price may not be a real bargain. Compare the final price with what other stores charge, not just the percent off the tag.
Sources: the percent formulas are standard arithmetic; the advice on reference prices follows the Federal Trade Commission’s Guides Against Deceptive Pricing, 16 CFR 233.1 (former price comparisons). Related: percentage calculator, sales tax calculator, tip calculator and margin calculator.