A standard drink is a fixed amount of pure alcohol, not a fixed glass size. Because drinks vary in strength, the serving that counts as one varies too.
| Drink | Serving | ABV | Standard drinks |
|---|---|---|---|
| Regular beer | 12 oz | 5% | 1 |
| Light beer | 12 oz | 4.2% | 0.8 |
| Malt liquor | 8 to 9 oz | 7% | 1 |
| Table wine | 5 oz | 12% | 1 |
| Fortified wine | 3 to 4 oz | 17% | 1 |
| Spirits (shot) | 1.5 oz | 40% | 1 |
| Cocktail | Varies | Varies | 1 to 3 |
One standard drink is 14 g of alcohol. In the US, one standard drink contains about 14 g of pure alcohol. A strong cocktail or craft beer can count as two or more, so it is easy to underestimate.
FAQ
Are standard drink sizes the same for alcohol and caffeine? No, they’re separate systems measuring different things. A standard alcoholic drink is defined by a fixed amount of pure alcohol regardless of beverage type, while standard caffeine servings are typically defined by beverage volume, not caffeine content.
See the Calories Per Drink Calculator and the Cocktail Mixing Ratios.