Alcohol proof is a measure of how much ethanol (alcohol) is contained in an alcoholic beverage. The term was originally used in the United Kingdom and was defined as 7/4 times the alcohol by volume (ABV). The UK now uses the ABV standard instead of alcohol proof. In the United States, alcoholic proof is defined as twice the percentage of ABV.
The measurement of alcohol content and the statement of this content on the bottle labels of alcoholic beverages is regulated by law in many countries. The purpose of the regulation is to provide pertinent information to the consumer.