wikiHow Discount Calculator To calculate a discount, you need to know the original price of an item and the percentage discount being offered. The formula for calculating the discount is: Discount = Original Price x Discount Rate where Discount Rate is the percentage of the original price that is being discounted. For example, if a $100 item is being offered at a 20% discount, the discount can be calculated as: Discount = $100 x 0.20 = $20 So, the discounted price would be: Discounted Price = Original Price - Discount = $100 - $20 = $80 Therefore, the discounted price of the item would be $80. Page