Blood/Breath Alcohol Concentration (BAC) calculator
Using the BAC calculator |
What can affect your BAC? |
Blood/Breath Alcohol Concentration (BAC) is the amount of alcohol in the
bloodstream or on one's breath. BAC is expressed as the weight of ethanol,
measured in grams, in 100 milliliters of blood, or 210 liters of breath. BAC can
be measured by breath, blood, or urine tests.
- Wisconsin defines legal intoxication for purposes of driving as having a
BAC of 0.08 or greater, in most cases. But alcohol may affect driving skills
at BACs of 0.05 or even lower.
- Driving skills, especially judgment, are impaired in most people long
before they show signs of drunkenness. The public usually associates BAC with
"drunk driving." But it's more accurate to refer to "alcohol-impaired" driving
because you do not have to be "drunk" to be impaired in your ability to safely
drive a car.
Use this calculator to instantly compute your estimated blood/breath alcohol
- Keep in mind the results generated are estimates.
- The primary purpose is to provide information about the responsible use of
Instructions: Please select weight, drinks consumed, time period and
gender and click the "compute your BAC" button:
- How much alcohol you drink.
- How fast you drink. In general, the quicker you drink, the higher your
peak BAC will be.
- Body size. Large people tend to reach lower BACs than smaller people,
given the same amount of alcohol.
- Food in your stomach. When there is food in your stomach, alcohol is
absorbed more slowly into the blood stream. The BAC rises more rapidly when
you drink on an empty stomach, because there is no food in which to dilute the
- Type of mixer used. Water and fruit juices mixed with alcohol may slow the
absorption process, while carbonated beverages may speed it up.
- Gender differences.
- Women reach higher BACs faster because they have less water in their
bodies and more adipose tissue (fat), which is not easily penetrated by
- A man and a woman, with all other factors being equal, both drinking the
same amount of alcohol, will have different BAC levels. Hers will be higher.
Your actual BAC is dependent on many complex factors, including your
emotional and physical condition and health, and what you've recently ingested
(including food, water, medications and other drugs).
- No blood/breath alcohol calculator is 100% accurate.
- The best that can be done is a rough estimation of your BAC level.
You should not consider this to be a guideline for how much you can drink
and still drive responsibly, or avoid being arrested! The best policy is don't
drink and drive. Period.
NOTE: The basic formula for estimating a person's blood/breath alcohol
concentration comes from the National
Highway Traffic Safety Administration.