Standard drink

A standard drink is a measure of alcohol consumption representing a hypothetical beverage which contains a fixed amount of pure alcohol. A standard drink varies in volume depending on the alcohol concentration of the beverage (for example, a standard drink of spirits takes up much less space than a standard drink of beer), but it always contains the same amount of alcohol and therefore produces the same amount of drunkenness.

For example, in the United States, a standard drink contains about 14 grams of alcohol. This roughly corresponds to a 12-US-fluid-ounce (350 ml) glass of beer, a 5-US-fluid-ounce (150 ml) glass of wine, or a 1.5-US-fluid-ounce (44 ml) glass of a spirit.

Different countries define standard drinks very differently. For example, in Australia, a standard drink contains 10 grams of alcohol, but in Japan, it contains nearly 20 grams. In addition, a standard drink is often different from normal serving size in the country in which it is served.

Labelling is usually required to give an indication of alcoholic content of a serving. Australia requires that "the label on a package of an alcoholic beverage must include a statement of the number of standard drinks in the package".