Blood Alcohol Concentration (BAC) refers to the percent of alcohol (ethyl alcohol or ethanol) in a person's blood stream. A BAC of .10% means that an individual's blood supply contains one part alcohol for every 1000 parts blood.

In California, a person is legally intoxicated if he/she has a BAC of .08% or higher.

Factors that determine BAC

Number of standard drinks (see below)

Amount of time in which drinks are consumed

Body weight

Biological Sex

Medications

Food (to a lesser extent)

For more information about alcohol metabolism, check out our alcohol metabolism page.

One standard drink

One 12 oz. regular beer (4.5% alcohol)

One 7 oz. malt liquor (7% alcohol)

One 5 oz. glass of wine (12% alcohol)

One 1.5 oz. shot of hard liquor (40% alcohol)

One-third jigger (.5 oz.) of Everclear (95% alcohol)

More than one standard drink

One 16 oz. cup of beer = 1.4 drinks

One 40 oz. beer = 3.6 drinks

One 22 oz. malt liquor = 3 drinks

One 12 oz. glass of wine = 2.9 drinks

One 12 oz. margarita = 2–4 drinks, depending on ingredients

One 12 oz. cup of trashcan punch = 4–10 drinks, depending on ingredients

Effects of alcohol at various Blood Alcohol Concentration levels