How to calculate the profit margin of a product: a simple case
Online Labels illustrates a product that costs $5.00 and sells for $15.00. The gross profit is $10.00. Divide $10.00 by the $15.00 price and the margin is 66.7%. Divide the same $10.00 by the $5.00 cost instead and you get a 200% markup.
Same product, same profit, two very different percentages. When a supplier, a retailer, or an investor quotes a percentage, ask which one they mean before you compare it with your own numbers.