Understanding Alcohol Content
Alcohol content is measured by how much alcohol is in a given amount of an alcoholic beverage. Wine, beer, and cider are usually listed as alcohol by volume (ABV), and liquor (distilled spirits) is labeled by “proof.”
Alcohol proof for distilled spirits is equal to twice the percentage of alcohol content by volume. For example, liquor that is 80 proof contains 40% alcohol by volume (ABV). For comparison, the average ABV for beer is as low as 5% but can be higher than 10%. The average ABV for wine is 11-13%. This makes a difference when thinking about how much alcohol you consume and what it means for your blood alcohol concentration.
Standard drink size
Knowing standard drink sizes will help you figure out how much alcohol is in your drink. By knowing this, you can make safer choices about how much you drink. One standard drink is defined as containing 0.6 ounces of pure alcohol.
The chart below demonstrates how the ABV varies depending on the type of alcohol. That means standard drink sizes will also vary.
| 12 oz. beer | 8-10 oz. malt liquor or flavored malt beverages like hard seltzer | 5 oz. wine | 1.5 oz. shot of distilled spirits (gin, rum, vodka, tequila, whiskey, etc. |
| Range from 5% to more than 10% alcohol | About 7% alcohol | About 12% alcohol | About 40% alcohol |
Calculating standard drinks
Because of the differences in alcohol levels in various types of alcoholic drinks, one “drink” may be more or less than a “standard drink.” You can find the number of standard drinks in a beverage by doing some simple math.
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The formula: the number of standard drinks = (volume) x (ABV) / 0.60
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Example: How many standard drinks are in a 16-ounce beer with a 9% (.09) ABV?
- X standard drinks = 16 x .09 / 0.60
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X = 2.4 standard drinks
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Example: How many standard drinks are in a 16-ounce beer with a 9% (.09) ABV?
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For alcohol labeled by “proof” rather than as ABV (for example many distilled spirits are labeled as 80% proof), find the ABV by dividing the proof in half (90 proof = 45% ABV).
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Let’s say you order a mixed drink cocktail that contains two different spirits for a total of 2.5 ounces of alcohol at 80 proof.
- X standard drinks = 2.5 x .40 / 0.60
- X = 1.6 standard drinks
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Let’s say you order a mixed drink cocktail that contains two different spirits for a total of 2.5 ounces of alcohol at 80 proof.
This standard drink calculator can do the math for you.
Why this is important
The liver processes the alcohol content of one standard drink per hour. Tracking how many standard drinks are being consumed can improve the ability to make responsible decisions and reduce the negative consequences of drinking too much alcohol.