In the United States, a standard drink contains 0.6 ounces (14 grams) of pure alcohol. That number stays the same regardless of what you’re drinking. What changes is the size of the glass, because beer, wine, and spirits all have different alcohol concentrations.
Standard Drink Sizes by Beverage
Each of these counts as one standard drink:
- Regular beer: 12 ounces at 5% alcohol by volume (ABV)
- Malt liquor or hard seltzer: 8 to 10 ounces at about 7% ABV
- Table wine: 5 ounces at 12% ABV
- Fortified wine (sherry, port): 3 to 4 ounces at about 17% ABV
- Cordial, liqueur, or aperitif: 2 to 3 ounces at about 24% ABV
- Distilled spirits (vodka, whiskey, rum, gin, tequila): 1.5 ounces at 40% ABV (80 proof)
- Brandy or cognac: 1.5 ounces (a single jigger) at about 40% ABV
The pattern is straightforward: the stronger the drink, the smaller the pour. A 12-ounce can of light beer and a 1.5-ounce shot of whiskey deliver the same amount of alcohol to your body.
Why Drinks in Real Life Often Don’t Match
The standard drink is a measurement tool, not a reflection of what actually ends up in your glass. A generous wine pour at a restaurant can easily hit 7 or 8 ounces, which is closer to 1.5 standard drinks. A pint glass of beer holds 16 ounces, not 12, so a single pint of 5% beer is already about 1.3 standard drinks.
Craft beer makes this especially tricky. Many craft IPAs and stouts run 7% to 9% ABV or higher. A 12-ounce can of a 9% double IPA contains roughly 1.8 standard drinks. If you drink two of those, you’ve had the equivalent of nearly four standard drinks, not two. Cocktails present a similar problem. A margarita or Long Island iced tea can contain two or three shots of liquor, meaning a single glass holds two to three standard drinks.
How to Calculate It Yourself
You can figure out how many standard drinks are in any container with a simple formula: multiply the volume in ounces by the ABV (as a decimal), then divide by 0.6. For example, a 16-ounce pint of 6% beer: 16 × 0.06 = 0.96, divided by 0.6 = 1.6 standard drinks.
For beer and malt beverages that don’t list the ABV on the label, you can usually find it on the brewer’s website. Wine and spirits are required to display the alcohol percentage on the container. The NIAAA also offers an online drink size calculator where you enter the volume and ABV, and it returns the number of standard drinks.
How Fast Your Body Processes Alcohol
Your liver processes roughly one standard drink per hour. That rate varies depending on your body size, sex, genetics, and whether you’ve eaten, but it’s a useful baseline. If you drink faster than your liver can keep up, alcohol accumulates in your bloodstream and your blood alcohol concentration rises.
This is why spacing matters as much as total count. Three drinks over five hours affects you very differently than three drinks in one hour, even though the total alcohol is the same.
How Standard Drinks Relate to Guidelines
U.S. health guidelines define moderate drinking as two drinks or fewer per day for men and one drink or fewer per day for women. Those numbers refer specifically to standard drinks, so knowing what counts as one is the foundation for tracking your intake accurately.
Binge drinking is defined as reaching a pattern of four or more drinks for women, or five or more drinks for men, during a single occasion. Because many real-world servings exceed one standard drink, it’s easier to cross that threshold than most people realize. Two large glasses of wine or two pints of strong craft beer can put someone at or near the binge drinking range without feeling like they’ve had “that much.”
The Proof System for Spirits
If you see “proof” on a bottle of liquor, divide it by two to get the ABV. An 80-proof vodka is 40% alcohol. A 100-proof bourbon is 50% alcohol, and a 1.5-ounce shot of it contains more than one standard drink. Some overproof spirits reach 120 or even 150 proof, meaning a single shot could count as 1.5 to nearly 2 standard drinks.
Knowing this conversion helps when you’re looking at a bottle that lists proof instead of percentage, which is common for American whiskey and rum.