Summary
To calculate the percentage discount from an original price and a sale price, you can use a formula that divides the difference by the original price. In the example shown, the formula in F5, copied down, is:
=(C5-D5)/C5
The result is a decimal value which is formatted with the percentage number format.
Generic formula
=(original_price-sale_price)/original_price
Explanation
In this example, the goal is to determine the percentage discount for each item shown in the table, given an original price and a sale price. In other words, given the Charcoal grill has an original price of $70.00 and a Sale Price of $59.50, we want to calculate a percentage discount of 15%, based on a price decrease of $10.50. Note that a discount of 15% represents the price change ($10.50) expressed as a percentage of the original price. To solve for the percentage when the price change is known, we can use a general formula like this:
original_price*x=price_change
x=price_change/original_price
x=10.50/70.00
x=0.15
However, since the price change is not in the table as a separate column, we need to add a step:
original_price*x=price_change
original_price*x=(original_price-sale_price)
x=(original_price-sale_price)/original_price
x=(70.00-59.50)/70.00
x=10.50/70.00
x=0.15
Applying this approach to the worksheet as shown, the formula in cell F5, copied down, is:
=(C5-D5)/C5
=(70-59.5)/70
=10.5/70
=0.15
For each item in the table, Excel returns a decimal value like 0.15, which the Percentage number format displays as 15%.
To calculate a sale price from a percentage discount, see Decrease by percentage. To work back from a sale price to the original price, see Get original price from percentage discount.
