In the United States, one standard drink contains 0.6 fluid ounces (14 grams) of pure alcohol. That’s the key number, and it stays the same no matter what you’re drinking. What changes is the size of the glass, because different beverages have different alcohol concentrations. A full pint of beer and a small shot of whiskey can contain the exact same amount of alcohol.
Standard Drink Sizes by Beverage
Since every type of alcohol has a different strength, the volume that equals one drink varies quite a bit. Here’s what one standard drink looks like for the most common categories:
- Regular beer (5% ABV): 12 fluid ounces, which is one typical can or bottle.
- Malt liquor (7% ABV): 8 to 9 fluid ounces. A standard 12-ounce can of malt liquor is closer to one and a half drinks.
- Table wine (12% ABV): 5 fluid ounces, roughly half a standard wine glass filled.
- Fortified wine like sherry or port (17% ABV): 3 to 4 fluid ounces.
- Distilled spirits at 80 proof (40% ABV): 1.5 fluid ounces, the size of a single shot.
The math behind all of these is the same. You multiply the volume by the alcohol percentage to arrive at 0.6 ounces of pure alcohol. If a craft beer is 8% ABV instead of 5%, that same 12-ounce can now contains nearly two standard drinks, not one.
Why Your Actual Pour Is Probably More
The standard drink is a measurement tool, not a reflection of what people actually pour or get served. A restaurant wine pour is typically 5 ounces, which lines up neatly with the definition. But at home, most people pour wine into large-bowled glasses and easily hit 7 or 8 ounces without thinking about it. That single glass is now one and a half drinks.
The same problem applies to cocktails. A strong mixed drink at a bar often contains 2 ounces or more of liquor, making it well over one standard drink before any mixers are added. A Long Island Iced Tea, for instance, can contain four or five shots across different spirits. Beer is the easiest to track because cans and bottles come in fixed, labeled sizes, but even here, craft beers and IPAs frequently run 7 to 10% ABV, which pushes a single 12-ounce can past the one-drink mark.
If you’re trying to keep an accurate count, the ABV listed on the label matters just as much as the volume in your glass.
How “Proof” Relates to ABV
In the U.S., proof is simply double the ABV percentage. An 80-proof vodka is 40% alcohol. A 100-proof bourbon is 50% alcohol, meaning a 1.5-ounce shot of it contains more pure alcohol than the standard drink definition. You’d need to pour closer to 1.2 ounces of a 100-proof spirit to stay at one standard drink.
How This Compares in Other Countries
The 14-gram standard is specific to the United States. Other countries define a standard drink differently. In the UK, one unit of alcohol equals 8 grams of pure alcohol, nearly half the U.S. definition. In Australia, a standard drink is 10 grams. This means health guidelines from different countries aren’t directly comparable. If you’re reading drinking recommendations from a British or Australian source, their “one drink” is a smaller amount of alcohol than the American version.
What Moderate Drinking Looks Like
Current U.S. guidelines from the CDC define moderate drinking as two drinks or fewer per day for men and one drink or fewer per day for women. These limits are based on the 14-gram standard drink, so the actual volume depends on what you’re drinking. Two standard drinks could be two 12-ounce regular beers, two 5-ounce glasses of wine, or two 1.5-ounce shots of 80-proof liquor.
The gap between the male and female thresholds reflects differences in body composition and how alcohol is metabolized. Women generally have less water in their bodies relative to their weight, so the same amount of alcohol produces a higher blood alcohol concentration.
Where Binge Drinking Starts
Binge drinking is defined as a pattern that brings blood alcohol concentration to 0.08% or higher. For a typical adult, that corresponds to five or more drinks for men, or four or more drinks for women, consumed in about two hours. Again, these numbers use the standard drink as their unit. If you’re drinking high-ABV craft beers or strong cocktails, you could reach binge-level consumption with fewer actual glasses than you’d expect.
Keeping a reliable count means paying attention to both how much liquid is in your glass and how strong it is. A 16-ounce pint of 7% IPA at a brewpub, for example, is about 1.9 standard drinks. Two of those pints in an evening puts most people past the moderate drinking threshold, even though it felt like “just two beers.”