Blood Alcohol Content Chart and Calculator

How alcohol affects blood alcohol level

blood alcoholAlcohol affects women differently than men. Women become more impaired than men do after drinking the same amount of alcohol, even when differences in body weight are taken into account. This is because women’s bodies have less water than men’s bodies. Because alcohol mixes with body water, a given amount of alcohol becomes more highly concentrated in a woman’s body than in a man’s. In other words, it would be like dropping the same amount of alcohol into a much smaller pail of water. That is why the recommended drinking limit for women is lower than for men.

In addition, chronic alcohol abuse takes a heavier physical toll on women than on men. Alcohol dependence and related medical problems, such as brain, heart, and liver damage, progress more rapidly in women than in men.

See National Institute on Alcohol Abuse and Alcoholism – No. 46 -December 1999, Alcohol Alert No. 46: Are Women More Vulnerable to Alcohol’s Effects?

Blood-Alcohol Content Calculator

A person’s blood-alcohol level is the result of a complex interaction of weight, gender, alcohol consumed, and time.

Weight (pounds)

Drinks Consumed
(12 ounces beer or equivalent)

Time Period (hours)





Alcohol Metabolism

Metabolism is the body’s process of converting ingested substances to other compounds. Metabolism results in some substances becoming more, and some less, toxic than those originally ingested. Metabolism involves a number of processes, one of which is referred to as oxidation. Through oxidation, alcohol is detoxified and removed from the blood, preventing the alcohol from accumulating and destroying cells and organs. A minute amount of alcohol escapes metabolism and is excreted unchanged in the breath and in urine. Until all the alcohol consumed has been metabolized, it is distributed throughout the body, affecting the brain and other tissues.

The Metabolic Process

When alcohol is consumed, it passes from the stomach and intestines into the blood, a process referred to as absorption. Alcohol is then metabolized by enzymes, which are body chemicals that break down other chemicals. In the liver, an enzyme called alcohol dehydrogenase (ADH) mediates the conversion of alcohol to acetaldehyde. Acetaldehyde is rapidly converted to acetate by other enzymes and is eventually metabolized to carbon dioxide and water. Alcohol also is metabolized in the liver by the enzyme cytochrome P450IIE1 (CYP2E1), which may be increased after chronic drinking (3). Most of the alcohol consumed is metabolized in the liver, but the small quantity that remains unmetabolized permits alcohol concentration to be measured in breath and urine. The liver can metabolize only a certain amount of alcohol per hour, regardless of the amount that has been consumed. The rate of alcohol metabolism depends, in part, on the amount of metabolizing enzymes in the liver, which varies among individuals and appears to have genetic determinants.

Effects of Alcohol Metabolism

Body Weight
Although alcohol has a relatively high caloric value, 7.1 Calories per gram (as a point of reference, 1 gram of carbohydrate contains 4.5 Calories, and 1 gram of fat contains 9 Calories), alcohol consumption does not necessarily result in increased body weight.

Sex Hormones
Alcohol metabolism alters the balance of reproductive hormones in men and women. In men, alcohol metabolism contributes to testicular injury and impairs testosterone synthesis and sperm production. In women, alcohol metabolism may contribute to increased production of a form of estrogen called estradiol (which contributes to increased bone density and reduced risk of coronary artery disease) and to decreased estradiol metabolism, resulting in elevated estradiol levels.

Chronic heavy drinking appears to activate the enzyme CYP2E1, which may be responsible for transforming the over-the-counter pain reliever acetaminophen (TylenolTM) and many others) into chemicals that can cause liver damage, even when acetaminophen is taken in standard therapeutic doses.