Calculate how many US standard drinks are in a given volume and alcohol percentage.
How It Works
How Standard Drink Calculator Works
The volume of the drink is multiplied by its ABV percentage and by the density of pure ethanol (about 0.789 g/ml) to get the grams of pure alcohol it contains — dividing that by 14 grams (the amount defined as one US standard drink) gives the number of standard drinks.
Worked Example
See It In Action
A typical 355 ml (12 oz) beer at 5% ABV contains about 14 grams of pure alcohol — almost exactly one standard drink, which is why that's the commonly cited reference serving.
FAQ
Frequently Asked Questions
Why isn't a "drink" always the same size?
A standard drink is defined by pure alcohol content, not volume — a small pour of strong liquor and a full glass of beer can both equal one standard drink despite looking very different in the glass, since it's the alcohol content that's equalized, not the liquid volume.
Does this account for how alcohol affects the body?
No — this only counts standard drinks based on alcohol content; individual factors like body weight, food intake, and metabolism all affect how alcohol actually impacts blood alcohol level, which the BAC calculator on this site addresses separately.
