A 12-ounce hard seltzer and 1.5 ounces of liquor are both considered standard drinks because they each contain approximately the same amount of pure alcohol, about 0.6 fluid ounces (or roughly 14 grams) of ethanol. This equivalence in pure alcohol content is what defines a standard drink, regardless of the volume or type of beverage. For example, a 12-ounce hard seltzer typically has about 5% alcohol by volume (ABV), which yields around 0.6 ounces of pure alcohol, similar to 1.5 ounces of distilled liquor that is typically 40% ABV (80 proof).
Definition of a Standard Drink
A standard drink is a measure used to quantify alcohol consumption based on the amount of pure alcohol it contains rather than the serving size or type of drink. In the U.S., this amount is 0.6 fluid ounces or 14 grams of pure alcohol. Different types of beverages contain varying alcohol concentrations, so the serving sizes differ to equalize the pure alcohol content.
Why Different Volumes but Equal Alcohol Content
Hard seltzers are typically lower in alcohol by volume (around 5%), so a larger volume (12 ounces) is required to reach the standard 0.6 ounces of pure alcohol. Liquor, especially spirits at 40% ABV, is much stronger, so a smaller volume (1.5 ounces) delivers the same amount of alcohol. This explains why both a 12-ounce hard seltzer and 1.5 ounces of liquor are considered equivalent standard drinks.
Thus, the key factor is that both beverages provide roughly the same dose of pure alcohol, aligning with standard drink guidelines to help people measure and moderate their alcohol intake responsibly.
