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) 100 120 130 140 150 160 170 180 190 200 210 220 230 240 250 260 270 280 290 300 Drinks Consumed (12 ounces beer or equivalent) 1 2 3 4 5 6 7 8 9 Over Time Period (hours) 1 2 3 4 5 6 Gender Female Male B.A.C.: The basic formula for estimating a person's blood-alcohol concentration comes from The National Highway Traffic Safety Administration. Each drink in this calculation assumes a volume of .54 ounces of alcohol (one shot of distilled spirits, a glass of wine, or 12 ounces of beer).

The basic formula for estimating a person's blood-alcohol concentration comes from The National Highway Traffic Safety Administration. Each drink in this calculation assumes a volume of .54 ounces of alcohol (one shot of distilled spirits, a glass of wine, or 12 ounces of beer). If the body metabolizes alcohol at a rate of one drink per hour, many of us have wondered just how many drinks it takes before we'd be considered legally drunk.

The Department of Justice estimates that over 1.4 million drivers were arrested for driving under the influence of alcohol or narcotics in 2005 (the latest data available). The arrest rate works out to one arrest for every 139 licensed drivers in the United States.

If you get pulled over and your blood-alcohol level is above the legal limit, you'll be arrested for drunk driving. If that leads to a conviction, it will result in a much higher car insurance premiums — if they let you drive at all.

This calculator helps you figure out what your blood-alcohol content would be if you drank a specific number of drinks over a certain period of time. Remember, this is just an approximation. Your blood alcohol level is affected by a number of factors including your age, weight, gender, time of day, physical condition, food consumed prior to taking a drink, other drugs or medication taken, and your tolerance level.

The calculator has to make certain assumptions, such as drinking alcohol on an empty stomach. If you eat while you drink, the alcohol is absorbed more slowly into your bloodstream. In any case, studies have shown that impairment begins with the first drink.

Alcohol affects everyone differently. If you rarely drink, you could be severely impaired by a single beer. For the most part, by the time you feel drunk, you're well past the legal limit.