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Alcohol's Effects on Health

Research-based information on drinking and its impact.

What Is A Standard Drink?

Knowing the number of standard drinks in alcohol-containing beverages can help you understand how much alcohol you are consuming and make informed decisions about your health. Yet, many people are surprised to learn what counts as a drink.  

Drinks like beer, wine, and distilled spirits often contain very different amounts of alcohol. This means the size of an alcohol-containing beverage alone does not determine its alcohol content. For example, many light beers have almost as much alcohol as regular beer – about 85% as much. Here’s another way to put it:

  • Regular beer: 5% alcohol by volume
  • Some light beers: 4.2% alcohol by volume
  • Some craft beers: 10% alcohol by volume

While a 12-ounce bottle of beer at 5% alcohol by volume contains one standard drink, a 12-ounce bottle of beer at 10% alcohol by volume contains two standard drinks. That’s why it’s important to know how much alcohol your drink contains. In the United States, one standard drink contains about 14 grams, or about 0.6 fluid ounces, of pure alcohol. That is the amount of alcohol in:

  • A 12-ounce can of regular beer at 5% alcohol by volume
  • A 5-ounce glass of wine at 12% alcohol by volume
  • A 1.5-ounce shot glass of distilled spirits at 40% alcohol by volume

How do you know how much alcohol is in your drink?

Even though they come in different sizes, the drinks below are each an example of one standard drink:

Each beverage portrayed above represents one standard drink, defined in the United States as any beverage containing 0.6 fl oz or 14 grams of pure alcohol. The percentage of pure alcohol, expressed here as alcohol by volume (alc/vol), varies within and across beverage types. Although the standard drink amounts are helpful for following health guidelines, they may not reflect customary serving sizes.

For more information, visit Rethinking Drinking.

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