One standard drink in the United States contains 0.6 fluid ounces (14 grams) of pure alcohol. That’s the amount found in 12 ounces of regular beer, 5 ounces of wine, or 1.5 ounces of distilled spirits. The actual glass, bottle, or can you’re drinking from almost never matches these numbers perfectly, which is why understanding the standard matters.
What Counts as One Standard Drink
The three most common forms each deliver the same 14 grams of pure alcohol when poured at their standard size and typical strength:
- Regular beer (5% ABV): 12 fluid ounces, roughly the size of a standard can or bottle.
- Table wine (12% ABV): 5 fluid ounces, which is noticeably less than most people pour at home.
- 80-proof spirits (40% ABV): 1.5 fluid ounces, a single standard shot glass.
These equivalences only hold at the ABV percentages listed. Change the alcohol concentration or the pour size, and you change how many standard drinks you’re actually consuming.
Why Your Drink Probably Isn’t “One Drink”
The standard drink is a measurement tool, not a reflection of how beverages are actually served. A typical restaurant wine pour is 6 ounces, not 5, which means it’s already 1.2 standard drinks before you’ve finished your first glass. Many cocktails contain two or even three shots of liquor, putting a single mixed drink at two standard drinks or more.
Craft beer is where the gap gets widest. A 16-ounce pint of a 9% ABV IPA contains about 2.4 standard drinks. You can calculate this yourself using a simple formula: multiply the volume in ounces by the ABV (as a decimal), then divide by 0.60. So for that pint: 16 × 0.09 ÷ 0.60 = 2.4. A 12-ounce can of a 7% beer works out to 1.4 standard drinks. Even a “light” craft lager at 4.2% in a 12-ounce can comes in slightly under one standard drink.
This math matters because most health guidelines, alcohol calculators, and BAC estimates are built on the standard drink unit. If you think you’ve had “two beers” but each was a high-ABV pint, your body processed closer to five standard drinks.
How Your Body Processes One Drink
Your liver breaks down alcohol at a relatively fixed rate. Most people lower their blood alcohol concentration by about 0.015 to 0.020 per hour. In practical terms, someone who reaches the legal driving limit of 0.08 BAC will need roughly four to five hours to return to zero. One standard drink for a typical adult raises BAC by approximately 0.02 to 0.03, depending on body weight, sex, food intake, and individual metabolism.
This is why spacing matters more than total quantity alone. Your liver can’t speed up because you’ve switched to water between rounds. If you’re drinking faster than your body metabolizes, alcohol accumulates in your bloodstream regardless of how “light” the beverage feels.
Current U.S. Drinking Guidelines
The Dietary Guidelines for Americans recommend that men limit intake to two drinks or fewer per day, and women to one drink or fewer per day, on days when alcohol is consumed. These limits are per-day ceilings, not averages. Having seven drinks on Saturday is not the same as one per night across a week, even though the weekly total matches.
Binge drinking is defined as a pattern that pushes BAC to 0.08 or higher, which typically corresponds to five or more drinks for men, or four or more for women, within about two hours. By that definition, splitting a bottle of wine with a friend over a short dinner can cross the threshold for many women, and a couple of high-ABV pints can do the same for men.
Standard Drinks Vary by Country
If you’re reading health research from outside the U.S., keep in mind that “one drink” doesn’t mean the same thing everywhere. A standard drink in the United Kingdom contains just 8 grams of pure alcohol, nearly half of the U.S. definition. Australia uses 10 grams. Canada uses 13.45 grams. This means a study from the UK reporting risk at “14 drinks per week” is describing a different amount of alcohol than an American study using the same number. When comparing international guidelines, convert to grams of pure alcohol rather than counting drinks.
How to Estimate Your Own Drinks
The formula (volume in ounces × ABV ÷ 0.60) works for any alcoholic beverage. A few common real-world examples:
- A 25-ounce (750 mL) bottle of wine at 13.5% ABV: about 5.6 standard drinks.
- A 12-ounce hard seltzer at 5% ABV: exactly 1 standard drink.
- A 12-ounce craft stout at 8% ABV: 1.6 standard drinks.
- A double cocktail with 3 ounces of 40% spirits: 2 standard drinks, before accounting for any liqueurs.
Check the label for ABV and the container size, then run the numbers. It takes about ten seconds and gives you a far more accurate picture than eyeballing it. Most people who track their intake this way discover they’ve been consistently undercounting.