Blood Alcohol Calculator (BAC Calculator)

Blood Alcohol Calculator (BAC Calculator) 2017-04-14T19:30:24+00:00

It’s possible to estimate your Blood Alcohol Content (BAC) with a Blood Alcohol Calculator for Oregon DUI prevention. Although the estimation may not be precise– and it will not necessarily prove or disprove intoxication or impairment– having information about your estimated Blood Alcohol Content (BAC) is helpful information in order to decide whether or not to continue drinking, gauging your estimated time of sobriety, deciding whether or not you should drive, and possibly deciding whether or not you should provide a breath test sample if requested by law enforcement. Due to errors and variability in breath test estimations, it’s important to note that your BrAC (Breath Alcohol Content) may not be the same as your true BAC (Blood Alcohol Content). However, the information can still be very helpful. Blood Alcohol Content (BAC) is usually expressed as a percentage of alcohol in the blood in units of mass of alcohol per mass of blood. In Oregon, there is a presumption that anyone operating a motor vehicle on public roads or premises open to the public is impaired by alcohol if a chemical analysis of the driver’s blood– by breath or blood– is equal or great than .08 percent by weight of alcohol. Keep in mind when using these calculators that a standard “drink” is assumed to be the equivalent of 13.7 grams (0.6 ounces) of pure alcohol (ethanol). Since we don’t normally weigh or measure our drinks when drinking socially, a good rule of thumb is as follows:

  • 12 ounces of beer = one “drink”
  • 8 ounces of malt liquor = one “drink”
  • 5 ounces of wine = one “drink”
  • 1.5 ounces or a “shot” of 80-proof distilled spirits or liquor (e.g. whiskey, bourbon, tequila, gin, rum, vodka, etc) = one “drink”

Be aware that many types of drinks have wildly different alcohol content and are served in different sizes. For example, a pint of a micro brew beer is not only going to have a higher percentage of alcohol than a 12 oz can of Coors Light beer, but a pint is a larger volume than a 12 oz can or bottle of beer.

The list of additional Blood Alcohol Calculators below is not a sponsorship, endorsement, or testimony for any of the sites on which the calculators are located or the accuracy of the calculators. In fact, the reason for providing a list is that it may be helpful to check your BAC on more than one calculator. That being said, the list below starts with BAC calculators on government websites. Curiously, even though the Oregon Department of Motor Vehicles (DMV) talks about commitments to driver safety, promotes campaigns against driving while impaired by drugs or alcohol, and even with all the grant funding available for special DUII programs and enforcement, the Oregon DMV does not provide an online Blood Alcohol Calculator. Thankfully, other states have been more pro-active and provide BAC calculators on their respective government websites.

In addition to the calculators above,  Eastern Illinois University has two BAC charts which provide a visual approximation of BAC based on sex, number of drinks, weight, and time elapsed.

If you have any questions about BAC calculations, please contact our office for further information.