A standard drink in the United States contains 0.6 fluid ounces (14 grams) of pure alcohol. That number stays the same regardless of what you’re drinking. What changes is the size of the serving, because different beverages have different alcohol concentrations.
What Counts as One Standard Drink
Since every type of alcohol has a different strength, the glass size that delivers exactly 0.6 ounces of pure alcohol varies quite a bit:
- Regular beer (5% ABV): 12 ounces, a typical can or bottle
- Malt liquor or hard seltzer (7% ABV): 8 to 10 ounces, not a full pint glass
- Wine (12% ABV): 5 ounces, roughly half a standard wine glass
- Distilled spirits (40% ABV / 80 proof): 1.5 ounces, a single shot
These are smaller than what most restaurants and bars actually pour. A generous glass of wine at dinner is often 8 or 9 ounces, which is closer to two standard drinks. A pint of craft beer can easily be two or more, depending on the strength.
Why Craft Beer and Strong Drinks Trip People Up
The standard drink framework was built around a 5% beer. Many popular craft beers sit at 7%, 8%, or even 10% ABV. A 12-ounce bottle of a 10% craft beer contains two full standard drinks, not one. If you’re drinking a 16-ounce pint of a 9% IPA at a brewery, that single glass holds 2.4 standard drinks.
Cocktails are similarly deceptive. A margarita or Long Island iced tea can contain two or three shots of liquor, meaning one cocktail might equal two to three standard drinks. Fortified wines like port and sherry, which typically run around 17 to 20% ABV, also pack more alcohol into a smaller pour. About 3 ounces of port equals one standard drink.
How to Calculate Standard Drinks Yourself
There’s a simple formula that works for any beverage. Multiply the volume in ounces by the ABV (expressed as a decimal), then divide by 0.6.
So for a 16-ounce pint of 9% beer: 16 × 0.09 = 1.44, divided by 0.6 = 2.4 standard drinks. For a 6-ounce glass of 14% wine: 6 × 0.14 = 0.84, divided by 0.6 = 1.4 standard drinks.
If a bottle lists proof instead of ABV, divide the proof number in half to get the ABV. An 80-proof whiskey is 40% ABV. A 100-proof bourbon is 50%.
How Fast Your Body Processes Alcohol
Your liver breaks down roughly 7 grams of alcohol per hour, which works out to about one standard drink per hour. That rate is fairly consistent across most adults, though body weight, sex, genetics, and whether you’ve eaten recently all shift it somewhat. Drinking faster than one standard drink per hour means alcohol accumulates in your bloodstream faster than your body can clear it, which is how blood alcohol levels climb.
Knowing this makes the standard drink measurement practical. If you had three glasses of wine over dinner and each glass was really 7 ounces of 13% wine, that’s not three standard drinks. It’s closer to 4.5. Your body would need roughly four and a half hours to fully process that amount.
Federal Guidelines for Moderate Drinking
The Dietary Guidelines for Americans (2020-2025) define moderate drinking as up to 2 standard drinks per day for men and up to 1 per day for women. These limits are based on standard drinks containing 0.6 ounces of pure alcohol, so underestimating your actual intake pushes you past the threshold without realizing it.
Standard Drinks Vary by Country
The 0.6-ounce (14-gram) definition is specific to the United States. Other countries define a standard drink differently. The UK uses 8 grams, Australia uses 10 grams, and some European countries use as much as 12 or 14 grams. If you’re reading health guidelines from another country, their “one drink” isn’t the same size as a U.S. standard drink. This matters most when interpreting international research on alcohol and health risks.