According to the American Medical Association, a
180 lb (82 kg) person who drinks three 12 ounce
(355 ml) bottles of beer in an hour will end up with a
BAC of about 0.06 percent. The person would reach the
same BAC by drinking three 4 ounce (120 ml) glasses
of wine or three mixed drinks if each had 1-1/2 ounces
(45 ml) of liquors like whiskey, gin, or vodka.
It is the amount of alcohol that counts. For example, if
the same person drank three double martinis (3 ounces
or 90 ml of liquor each) within an hour, the person’s BAC
would be close to 0.12 percent. A person who consumes
food just before or during drinking will have a somewhat
lower BAC level.
There is a gender difference, too. Women generally
have a lower relative percentage of body water than men.
Since alcohol is carried in body water, this means that a
woman generally will reach a higher BAC level than a
man of her same body weight will when each has the
same number of drinks.
The law in most U.S. states, and throughout Canada,
sets the legal limit at 0.08 percent. In some other
countries, the limit is even lower. For example, it is
0.05 percent in both France and Germany. The
BAC limit for all commercial drivers in the United States
is 0.04 percent.
The BAC will be over 0.10 percent after three to
six drinks (in one hour). Of course, as we have seen, it
depends on how much alcohol is in the drinks, and
how quickly the person drinks them.
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