Campus Health

Blood/Breath Alcohol Concentration (BAC) Calculator

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.

  • Louisiana 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.

Using the BAC calculator

Use this calculator to instantly compute your estimated blood/breath alcohol concentration.

  • But keep in mind the results generated are estimates.
  • The primary purpose is to provide information about the responsible use of alcohol.

Instructions: Please select weight, drinks consumed, time period and gender and click the "compute your BAC" button:

Weight (pounds)

Drinks consumed
(12 ounces beer or equivalent)

Over time period (hours)





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