It is a common size for liquor bottles in the United States. A fifth, also known as a standard bottle, is equivalent to 750 milliliters (ml) or 25.36 fluid ounces (fl oz) of liquid.

A fifth of alcohol is typically used to describe bottles of hard liquor, such as whiskey, vodka, gin, or rum. This size bottle usually contains around 17-20 shots of alcohol, depending on the strength of the liquor and the size of the shot being poured.
It’s worth noting that the alcohol content of a fifth can vary widely depending on the type of liquor. For example, a fifth of 80-proof (40% alcohol by volume) liquor contains 25.36 fl oz of liquid, but a fifth of 100-proof (50% alcohol by volume) liquor would contain more alcohol in the same amount of liquid.
It’s also important to keep in mind that consuming large amounts of alcohol can have negative health effects, including impaired judgment, loss of coordination, and alcohol poisoning. The legal drinking age in the United States is 21, and it’s recommended that adults consume alcohol in moderation, which is defined as up to one drink per day for women and up to two drinks per day for men.
In summary, a fifth of alcohol refers to a standard liquor bottle size of 750 ml or 25.36 fl oz, which typically contains around 17-20 shots of hard liquor. However, it’s important to consume alcohol in moderation and be aware of the alcohol content of the specific type of liquor being consumed.