A standard drink in the United States contains 0.6 fluid ounces of pure alcohol. That’s roughly 14 grams. The fluid ounces of the actual beverage you’re drinking, though, depend entirely on what’s in your glass, because different drinks have different alcohol concentrations.
Ounces per Standard Drink by Beverage Type
Since a standard drink is defined by how much pure alcohol it contains (0.6 ounces), the total volume of liquid changes based on the drink’s strength:
- Regular beer (5% ABV): 12 ounces
- Table wine (12% ABV): 5 ounces
- Distilled spirits (40% ABV): 1.5 ounces
- Fortified wine like port (17% ABV): 3 to 4 ounces
These numbers come from the National Institute on Alcohol Abuse and Alcoholism (NIAAA) and form the basis for nutrition labels, health guidelines, and moderate drinking recommendations in the U.S. The Dietary Guidelines for Americans, 2020–2025 recommend limiting intake to two drinks or fewer per day for men and one drink or fewer per day for women, with each “drink” referring to these standard amounts.
Why Your Drink Probably Isn’t “Standard”
The standard drink is a reference point, not a reflection of what people actually pour or order. A pint of beer at a bar is 16 ounces, not 12. A generous wine pour at home can easily hit 7 or 8 ounces. A cocktail with two shots of liquor contains 3 ounces of spirits, which is two standard drinks in a single glass.
Alcohol content varies widely too. A light lager might clock in at 4% ABV, while a craft IPA often sits between 6% and 9%. That 16-ounce pint of 9% beer contains 2.4 standard drinks, not one. Wine ranges from about 11% for a light white to 15% or more for a bold red, meaning the same 5-ounce pour can deliver noticeably different amounts of alcohol.
Restaurant wine pours generally do land close to 5 ounces, which aligns with one standard drink for table wine. But there’s no legal requirement for a specific pour size, and unlike pints of beer, there’s no official standard measure for a glass of wine.
How to Calculate Standard Drinks Yourself
If you want to know exactly how many standard drinks are in any container, there’s a simple formula. Multiply the volume in ounces by the ABV (as a decimal), then divide by 0.6.
For example, a 16-ounce craft beer at 9% ABV: 16 × 0.09 = 1.44, divided by 0.6 = 2.4 standard drinks. A 25-ounce bottle of wine at 13.5% ABV: 25 × 0.135 = 3.375, divided by 0.6 = about 5.6 standard drinks, meaning a bottle holds roughly five and a half drinks rather than the four or five glasses many people assume.
If a bottle lists “proof” instead of ABV (common with spirits), divide the proof by two to get the ABV. An 80-proof vodka is 40% ABV. A 90-proof bourbon is 45% ABV, so a 1.5-ounce shot of that bourbon is slightly more than one standard drink: 1.5 × 0.45 / 0.6 = 1.125.
Standard Drinks Vary by Country
There is no international definition of a standard drink. The U.S. sets it at 0.6 ounces (14 grams) of pure ethanol, but other countries draw the line differently. Canada’s standard drink contains roughly 0.58 U.S. fluid ounces of pure ethanol (17.05 mL), which is slightly less than the American version. The UK uses “units” rather than standard drinks, with one unit equaling 8 grams of alcohol, about 57% of a U.S. standard drink. Australia sets its standard at 10 grams.
These differences matter if you’re reading health guidelines from another country. A recommendation to stay under “two units” in the UK is not the same as “two drinks” in the U.S. Always check which country’s definition is being used.
Common Drinks That Contain More Than One Standard Drink
Many popular drinks pack more alcohol than a single standard drink, even though they arrive in one glass or one can. Knowing which ones catch people off guard can help you track what you’re actually consuming:
- A margarita: Typically uses 2 to 3 ounces of tequila, making it roughly 1.5 to 2 standard drinks.
- A pint of 7% IPA: 16 × 0.07 / 0.6 = about 1.9 standard drinks.
- A large (9-ounce) glass of 14% red wine: 9 × 0.14 / 0.6 = 2.1 standard drinks.
- A tall can of hard seltzer (16 ounces at 8% ABV): 16 × 0.08 / 0.6 = about 2.1 standard drinks.
The gap between “one drink” and “one standard drink” is where most miscounting happens. Using the formula above takes a few seconds and gives you a much more accurate picture of your intake than eyeballing it.