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 12% wine (no longer the norm, however), or a 1.5-US-fluid-ounce (44 ml) glass of a spirit.

Different countries define standard drinks 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.

Labeling 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".

The term "standard drink" was used in the United Kingdom in the first guidelines (1984) that published "safe limits" for drinking, but this was replaced by reference to "alcohol units" in the 1987 guidelines and that term has been used in all subsequent UK guidance. A unit of alcohol is defined as 10 millilitres (8 grams) of pure alcohol. This definition is independent of the strength (% ABV) and amount (volume) of any individual alcoholic beverage. The number of units of alcohol in a bottle or can (and, optionally, the number of units in a typical serving) are indicated on the drink container. Typical servings deliver 1–3 units of alcohol.

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