What Happens at Various Levels of Blood Alcohol Content (BAC)?

Compiled by Jon Weeldreyer, MA, CAAC

Blood alcohol content is usually expressed as a percentage of alcohol (generally in the sense of ethanol) in the blood. For instance, a BAC of 0.10 means that 0.10% (one tenth of one percent) of a person's blood, by volume is alcohol.

Blood alcohol content levels

Note: Many factors influence how many drinks it takes to reach a particular BAC, including age, gender, rate of consumption, drink strength, body type, fat/muscle content, metabolism, hydration, emotional state, medication you are taking, food you’ve consumed, carbonation of drinks, alcohol tolerance and overall health.