Discount calculator: sale price, savings and stacked discounts
Enter the original price and the discount. 25% off $120 saves $30, so the sale price is $90. An extra 10% off the sale price brings it to $81, a combined 32.5% discount, not 35%.
Inputs used by this calculator
Discount Calculator uses the fields below. The starting values reproduce the page example; replace them with values from the same units and time period before using the result.
| Input | Starting example | Accepted value | How it is used |
|---|---|---|---|
| Original price | 120 | 0 or greater | Supplies the original price quantity used by the published equation or result breakdown. |
| Discount (%) | 25 | 0 to 100 | Supplies the discount (%) quantity used by the published equation or result breakdown. |
| Extra discount after the first (%) | 0 | 0 to 100 | Supplies the extra discount after the first (%) quantity used by the published equation or result breakdown. |
How a percent-off discount works
Multiply the price by the discount as a decimal to find the savings, then subtract. 25% off $120 is 120 × 0.25 = $30, leaving $90. Equivalently, multiply by what remains: 120 × 0.75 = 90.
savings = price × discount ÷ 100sale price = price × (1 − discount ÷ 100)Stacked discounts
“An extra 10% off sale prices” applies to the reduced price, so discounts multiply rather than add. 25% off and then 10% off leaves 0.75 × 0.90 = 0.675 of the price, a combined discount of 32.5%. The table shows several combinations.
Percent off versus dollars off
A $20-off coupon is worth more than 10% off on items under $200 and less on items above. Convert both to dollars for the item you are buying before choosing.
Sales tax comes after the discount
In most places, sales tax is charged on the discounted price. For the total at the register, use the Percent Off Calculator, which applies the discount and then the tax rate.
Is the original price real?
The FTC's Guides Against Deceptive Pricing describe a former price as one at which the item was actually offered to the public on a regular basis for a reasonably substantial period. A large percent off an inflated “original” price is not a real saving; compare prices across stores.
Working backward
To find the original price from a sale price, divide by what remains: a $90 sale price after 25% off came from 90 ÷ 0.75 = $120. To find the discount rate, divide the savings by the original price.
Stacked discounts on a $120 item
| Discounts | Final price | Combined discount |
|---|---|---|
| 25% only | $90.00 | 25% |
| 25% then 10% | $81.00 | 32.5% |
| 25% then 15% | $76.50 | 36.25% |
| 25% then 20% | $72.00 | 40% |
Frequently asked questions
How do I calculate a discount?
Multiply the price by the percent off and divide by 100; subtract that from the price.
What is 25% off $120?
$30 off, for a sale price of $90.
Do two discounts add up?
No. 25% and then 10% is 32.5% combined, because the second discount applies to the lower price.
Is tax calculated before or after the discount?
Usually after, on the discounted price.
How do I find the original price?
Divide the sale price by (1 − discount rate).
Is 40% off always a good deal?
Only if the original price was real; compare with other stores.
What discount do I get from a $20-off coupon?
Divide $20 by the price: on a $100 item it is 20%.
What to keep in mind
Tax, shipping and additional discounts are not included.
Results are rounded for display in US format, with money in dollars and cents; CSV exports keep full calculation precision. This is a calculation summary, not an official certificate.