Standard drink

A standard drink or (in the UK) unit of alcohol is a measure of alcohol consumption representing a fixed amount of pure alcohol. The notion is used in relation to recommendations about alcohol consumption and its relative risks to health. It helps to educate alcohol users. A hypothetical alcoholic beverage sized to one 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. Many government health guidelines specify low to high risk amounts in units of grams of pure alcohol per day, week, or single occasion. These government guidelines often illustrate these amounts as standard drinks of various beverages, with their serving sizes indicated. Although used for the same purpose, the definition of a standard drink varies from country to country. Labeling beverages with the equivalent number of standard drinks is common in some countries. There is no international consensus on how much pure alcohol is contained in a standard drink; values in different countries range from 8g to 20g. The example questionnaire form for the World Health Organization's Alcohol Use Disorders Identification Test (AUDIT) uses 10g, and this definition has been adopted by more countries than any other amount. Some countries choose to base the definition on mass of alcohol (in grams) while others base the unit on the volume (in mL or other volume units). For comparison, both measurements are shown here, as well as the number of standard drinks contained in 500 mL of 5% ABV beer (16.9 US fl oz, a typical large size of beer in Europe, slightly larger than a US pint of 473ml). The terminology for the unit also varies, as shown in the Notes column. In the UK, it is sometimes misleadingly stated that there is one unit per half-pint of beer, or small glass of wine, or single measure of spirits.