How Percent Off and Stackable Discounts Work
A percent off of a product or service is a common discount format in retail. A percent off of a product means that the price of the product is reduced by that percent. For example, given a product that costs $279, a 20% discount would mean subtracting 20% of the original price from the original price.
Single Discount Calculation
Using the $279 item with a 20% markdown:
You would therefore save $55.80 on the purchase for a final price of $223.20. Equivalently: Final Price = $279 × (1 - 0.20) = $223.20.
Stackable Additional Discounts (Coupons on Top of Sale Prices)
For this calculator, a "stackable additional discount" means receiving a further percent off after an initial markdown is applied.
Assume the 20% discount is applied by the store. If you present a coupon for another 15% off, the second discount applies to the discounted price of $223.20, not to the original $279:
This equates to a 32% effective discount ($89.28 ÷ $279), rather than 35% (20% + 15%). The efficient calculation is:
Solving for Any Two Values
This tool allows you to input any 2 of the 4 variables (Original price, Percent off, Final price, Saved amount) to calculate the remaining two. If you know how much you paid ($33.99) and what the discount was (15%), it will accurately compute the initial MSRP ($39.99) and your savings ($6.00).