A standard drink in the United States contains about 0.6 fluid ounces of pure alcohol. That’s roughly 14 grams. Every type of alcoholic beverage, from light beer to whiskey, is measured against this same number, though the total liquid in your glass changes depending on how strong the drink is.
What Counts as One Standard Drink
The 0.6-ounce figure is the common thread, but the serving size that gets you there varies widely. Here are the standard equivalents:
- Regular beer (5% ABV): 12 fluid ounces, or one typical can or bottle
- Malt liquor or hard seltzer (7% ABV): 8 to 10 fluid ounces
- Wine (12% ABV): 5 fluid ounces
- Fortified wine like sherry or port (17% ABV): 3 to 4 fluid ounces
- Liqueur or cordial (24% ABV): 2 to 3 fluid ounces
- Distilled spirits like vodka, rum, whiskey, or tequila (40% ABV): 1.5 fluid ounces, or one standard shot
The math is straightforward. Multiply the volume of the drink by its alcohol percentage, and you should land close to 0.6 ounces of pure alcohol. A 12-ounce beer at 5% gives you 0.6 ounces. A 1.5-ounce shot of 40% whiskey also gives you 0.6 ounces. Same alcohol, very different glass.
Why Your Actual Drink Often Contains More
The standard drink is a reference point, not a description of what’s actually in front of you. In practice, most drinks contain more alcohol than one standard serving. A pint of beer at a bar is 16 ounces, not 12, which bumps it to about 1.3 standard drinks. Craft beers frequently run 7% to 9% ABV or higher, meaning a single pint could equal nearly two standard drinks.
Wine pours are similarly inconsistent. While the official standard is 5 ounces, many restaurants and wine bars pour 6 to 9 ounces per glass. A generous 9-ounce pour of 12% wine contains almost two standard drinks’ worth of alcohol. At home, without a measured pour, most people fill the glass well past the 5-ounce line without realizing it.
Mixed cocktails are the hardest to gauge. A margarita or Long Island iced tea can contain two, three, or even four shots of spirits depending on the recipe and the bartender. One cocktail can easily represent two or more standard drinks.
How to Calculate It Yourself
If you know the ABV (alcohol by volume) listed on the label and the size of your pour, you can figure out the number of standard drinks with a simple formula: multiply the total ounces by the ABV percentage (as a decimal), then divide by 0.6.
For example, a 16-ounce pint of craft beer at 8% ABV: 16 × 0.08 = 1.28 ounces of pure alcohol. Divide 1.28 by 0.6, and you get about 2.1 standard drinks in that single pint. A 6-ounce glass of 14% red wine: 6 × 0.14 = 0.84 ounces of alcohol, or 1.4 standard drinks.
This calculation is especially useful for higher-ABV beverages where a single serving looks modest but packs more alcohol than you’d expect.
How Fast Your Body Processes One Drink
Your liver breaks down alcohol at a fairly fixed rate: roughly one standard drink per hour. That pace doesn’t speed up with coffee, food, water, or a cold shower. If you have three standard drinks, it takes approximately three hours for your body to fully metabolize the alcohol.
Because the rate is constant, drinking faster than one standard drink per hour means alcohol accumulates in your bloodstream. This is why the actual alcohol content of what you’re drinking matters so much. Two craft IPAs over dinner could contain four standard drinks’ worth of alcohol, requiring about four hours to clear, not two.
Where the Guidelines Draw the Line
The U.S. Dietary Guidelines define moderate drinking as up to two standard drinks per day for men and one per day for women. Those numbers assume each drink actually contains 0.6 ounces of pure alcohol. If your “one glass of wine” is really a 9-ounce pour, you’ve already exceeded the guideline for women and nearly hit the limit for men, all from what feels like a single drink.
Understanding the 0.6-ounce baseline makes it possible to honestly track how much you’re consuming, rather than counting “drinks” that vary wildly in actual alcohol content.