Blood Alcohol Concentration

Blood Alcohol Concentration (BAC): Your body is made up of about 6 quarts (or 5.6 liters) of blood. BAC is recorded in milligrams of alcohol in 100 milliliters of blood. A BAC of 0.10 means that 1/10 of 1 percent of your total blood is alcohol. This means that 1/1000 of your total blood content is alcohol. This is about 5 milliliters or a quarter of a one quart milk container.

Body Weight:

  • Weight determines how much water is in your body to dilute alcohol.


  • Men often have more body weight to dilute alcohol.
  • Women typically have 70% to 80% less of a stomach enzyme alcohol dehydrogenase, which aids in the metabolism of alcohol before it enters the bloodstream.
  • Fluctuations in hormones (related to a woman’s menstrual cycle) will also affect one’s BAC. One week before and one week after menstruating women are likely to stay intoxicated for longer periods of time.
  • Increases in estrogen whether related to one’s natural cycle or oral contraceptives (birth control pills) will likely lead to longer periods of peak intoxication than they would otherwise.


  • The amount of time you spend consuming alcohol.

Amount of Alcohol Consumed:

  • Knowing how to identify a standard drink is necessary for calculating blood alcohol concentrations. The following chart outlines what a standard drink looks like. Please note that mixed drinks may not be measured and may contain more than 1.25/1.0 oz of alcohol. Drinks containing high proof alcohol (Everclear, grain alcohol etc) should be treated with caution.

drink comparison image