Most of the time, “40 ounce” means a single glass bottle of malt liquor, which is a type of beer known for having a high alcohol content by volume. Other beers that come in smaller glass bottles and aluminium cans can be combined to make a total of 40 ounces. This depends on how big each bottle or can is.
The most common size of beer can and bottle in the United States is 12 ounces. At this size, you’d need three and a quarter beers to get to 40 ounces. Some beers also come in a “Tall Boy” size of 24 ounces. In the late 1980s and early 1990s, many rappers made the 40-ounce popular.