In the United States, one standard alcoholic drink contains about 14 grams (0.6 fluid ounces) 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%, or a 1.5-ounce shot of 80-proof liquor at 40%. The catch is that many of the drinks people actually pour, order, or buy don’t line up neatly with those numbers.
The Standard Drink, Broken Down
The standard drink isn’t about the type of beverage. It’s about how much pure alcohol ends up in your glass. All three of the most common drink types deliver the same 0.6 ounces of alcohol when served at their typical strength and size:
- Regular beer: 12 ounces at 5% ABV
- Table wine: 5 ounces at 12% ABV
- Distilled spirits: 1.5 ounces at 40% ABV (80 proof)
Fortified wines like port or sherry sit between regular wine and spirits. They typically range from 17% to 20% ABV, so a standard drink is only about 3 to 4 ounces rather than the full 5-ounce wine pour.
Why Your Drink Probably Isn’t “One Drink”
The standard drink is a measurement tool, not a description of what’s actually in your glass. A pint of craft IPA at 7% ABV contains nearly 1.9 standard drinks. A 12-ounce bottle of a 10% imperial stout contains two full standard drinks, even though it looks like any other single beer. A generous restaurant wine pour of 8 ounces at 14% ABV works out to roughly 1.9 standard drinks as well.
Cocktails are especially tricky. A margarita or Long Island iced tea can contain two, three, or even four standard drinks depending on the recipe and the bartender’s hand. A single mixed drink at a bar is not necessarily one standard drink.
Hard seltzers and canned cocktails have made this even more confusing. Many are designed to contain exactly one standard drink per can, but some come in taller 16- or 24-ounce cans with higher ABV, pushing them to two or three standard drinks per container.
How to Calculate Standard Drinks
If you know the total volume in ounces and the ABV percentage, you can figure out how many standard drinks are in any container. The formula is straightforward: 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 9% ABV: 16 × 0.09 = 1.44, divided by 0.6 = 2.4 standard drinks. That single pint glass holds nearly two and a half drinks by the federal definition. A 750ml bottle of wine (about 25 ounces) at 13.5% ABV works out to roughly 5.6 standard drinks, not the four or five glasses many people assume they’ll get.
What Counts as “Non-Alcoholic”
The FDA draws a line between “alcohol-free” and “non-alcoholic,” and they don’t mean the same thing. A product labeled “alcohol-free” must contain no detectable alcohol at all. A “non-alcoholic” beverage can contain up to 0.5% ABV, which is roughly the trace amount that occurs naturally in some fruit juices and fermented foods. At that level, you would need to drink dozens of non-alcoholic beers in a short period to approach the alcohol content of a single standard drink.
Moderate Drinking Guidelines
The Dietary Guidelines for Americans defines moderate drinking as two standard drinks or fewer per day for men and one standard drink or fewer per day for women. These limits assume you’re counting actual standard drinks, not just the number of glasses or cans you’ve had. If your evening beer is a 9% double IPA in a pint glass, that single pour already exceeds the daily guideline for women and gets close to the limit for men.
This is why understanding the standard drink matters in practical terms. People who believe they’re having “just two beers” may actually be consuming three or four standard drinks depending on what they’re drinking and how it’s served.
Standard Drinks Vary by Country
If you’re reading health guidelines from outside the United States, the numbers won’t match up. A UK alcohol unit contains 8 grams of pure alcohol, compared to 14 grams in a US standard drink. That means one US standard drink equals about 1.75 UK units. Australia uses 10 grams as its standard, and many European countries use 10 or 12 grams. When comparing your drinking to international health recommendations, you need to know which system those recommendations use, or the math won’t add up.