The amount of real cheese in American cheese will depend on the brand and the particular product. However, the U.S. Food & Drug Administration (USDA) mandates that any product using the name 'American cheese' must contain at least 51% real cheese. We can see this in their Code of Federal Regulations for cheeses and related cheese products in section 133.124(5): "The weight of the cheese ingredient constitutes not less than 51 percent of the weight of the finished cold-pack cheese food" (22).