A standard drink in the United States contains 0.6 fluid ounces (14 grams) of pure alcohol. That’s the amount found in a 12-ounce beer at 5% alcohol by volume, a 5-ounce glass of wine at 12% ABV, or a 1.5-ounce shot of distilled spirits at 40% ABV. These three servings look very different in the glass, but they all deliver the same amount of alcohol to your body.
Why the Serving Size Changes by Drink
The reason a “drink” means 12 ounces of beer but only 1.5 ounces of whiskey comes down to concentration. Beer is mostly water with a relatively low alcohol percentage, so you need a larger volume to reach 0.6 ounces of pure alcohol. Spirits pack the same alcohol into a much smaller space. Wine falls in between. The standard drink system exists to make these very different beverages comparable, giving you a consistent unit for tracking how much alcohol you’re actually consuming.
How to Calculate Standard Drinks
You can figure out how many standard drinks are in any container using a simple formula from the Washington State Liquor and Cannabis Board: multiply the volume in ounces by the ABV (as a decimal), then divide by 0.6.
For example, a 16-ounce pint of beer at 7% ABV: 16 × 0.07 = 1.12 ounces of pure alcohol. Divide by 0.6, and that pint contains roughly 1.9 standard drinks. A 25-ounce bottle of wine at 13.5% ABV works out to about 5.6 standard drinks.
This formula is especially useful for craft beers, cocktails, and wine pours that don’t match the neat 12/5/1.5-ounce templates.
Craft Beer and Real-World Pours
The standard drink framework was built around a 5% ABV beer, but many popular craft beers now range from 6% to 10% or higher. The NIAAA points out that a 12-ounce bottle of 10% ABV beer contains two standard drinks, not one. A 16-ounce draft pour of an 8% IPA clocks in at about 2.1 standard drinks.
Wine pours at restaurants often exceed 5 ounces, and cocktails frequently contain more than one shot of spirits. A margarita or Long Island iced tea can easily hold two to three standard drinks in a single glass. The gap between “one drink” as you experience it socially and “one standard drink” as a unit of measurement is often significant.
Your Body Processes About One Drink Per Hour
The liver breaks down alcohol at a remarkably steady rate: roughly one standard drink per hour. You can’t speed this up with coffee, food, or water. Those might help you feel more alert, but the alcohol is still in your bloodstream until your liver works through it.
This means that if you have three standard drinks between 8 and 9 p.m., your body won’t fully clear that alcohol until around midnight. If that “three drinks” was actually closer to five standard drinks because of strong pours or high-ABV beers, you’re looking at closer to 2 a.m. This is why the standard drink calculation matters for practical decisions like driving.
How Standard Drinks Relate to Guidelines
Federal health guidelines use standard drinks as their measuring stick. The CDC defines moderate drinking as two drinks or fewer per day for men and one drink or fewer per day for women. Binge drinking, as defined by the NIAAA, means reaching a blood alcohol concentration of 0.08%, which for a typical adult corresponds to five or more drinks for men, or four or more for women, in about two hours.
The Dietary Guidelines for Americans note that adults of legal drinking age can choose not to drink or to drink in moderation. The CDC adds a caveat worth knowing: even moderate drinking may increase your risk of death and other alcohol-related harms compared to not drinking at all.
Labels Don’t Tell You
You might expect alcohol labels to list how many standard drinks a container holds, but U.S. federal law doesn’t require it. The Alcohol and Tobacco Tax and Trade Bureau (TTB) does not mandate that labels disclose standard drink counts, calorie content, or a full ingredient list. As of early 2024, the TTB has been considering whether to require this information, following recommendations that labels should include alcohol content, nutritional facts, and appropriate serving sizes. For now, though, you’ll need to do the math yourself using the ABV percentage printed on the label and the formula above.
This is one of the biggest practical gaps in alcohol packaging. A 750-mL bottle of 14% wine contains about five standard drinks, but nothing on the label says so. A four-pack of 16-ounce, 9% double IPAs holds the equivalent of nearly 10 standard drinks, which many people would not guess from looking at four cans.