The difference between margin and markup is critical for business profitability. Margin is the ratio of profit to the selling price, while markup is the ratio of profit to the cost price.

1. Gross Profit = Revenue - Cost
2. Margin (%) = (Gross Profit / Revenue) * 100
3. Markup (%) = (Gross Profit / Cost) * 100

For example, if an item costs $100 and sells for$150, the Gross Profit is $50. The Margin is 33.33$50/$150), and the Markup is 50$50/$100).