How To Calculate Your Estimated Blood Alcohol Content (BAC)

Showing estimated percent of alcohol in the blood by number of drinks in relation to body weight. This percent can be estimated by:

  1. Count your drinks (1 drink equals 1 ounce of 100-proof liquor, one five ounce glass of table wine or one 12-ounce bottle of regular beer).
  2. Use the chart below and under number of “drinks” and opposite “body weight” find the percent of blood alcohol listed.
  3. Subtract from this number the percent of alcohol “burned up” during the time elapsed since your first drink. This figure is .015% per hour. (Example: 180 lb. man – 8 drinks in 4 hours / .167% minus (.015×4) = .107 %

Drinks

Understanding BAC Levels & Effects

Common symptoms, levels of impairment, and risks for various blood alcohol concentration (BAC) levels include:

  • 0.02%: This is the lowest level of intoxication with some measurable impact on the brain and body. You will feel relaxed, experience altered mood, feel a little warmer, and may make poor judgments.
  • 0.05%: At this level of BAC, your behavior will may become exaggerated. You may speak louder and gesture more. You may also begin to lose control of small muscles, like the ability to focus your eyes, so vision will become blurry.
  • 0.08%: This is the current legal limit in the U.S., other than Utah, and at this level it is considered illegal and unsafe to drive. You will lose more coordination, so your balance, speech, reaction times, and even hearing will get worse.
  • 0.10%: At this BAC, reaction time and control will be reduced, speech will be slurred, thinking and reasoning are slower, and the ability to coordinate your arms and legs is poor.
  • 0.15%: This BAC is very high. You will have much less control over your balance and voluntary muscles, so walking and talking are difficult. You may fall and hurt yourself.
  • 0.20-0.29%: Confusion, feeling dazed, and disorientation are common. Sensations of pain will change, so if you fall and seriously hurt yourself, you may not notice, and you are less likely to do anything about it. Nausea and vomiting are likely to occur, and the gag reflex will be impaired, which could cause choking or aspirating on vomit. Blackouts begin at this BAC, so you may participate in events that you don’t remember.
  • 0.30-0.39%: At this point, you may be unconscious and your potential for death increases. Along with a loss of understanding, at this BAC you’ll also experience severe increases in your heart rate, irregular breathing and may have a loss of bladder control.
  • 0.40% and over: This level of BAC may put you in a coma or cause sudden death because your heart or breathing will suddenly stop. This is what is known as a lethal blood alcohol level.

Source: www.alcohol.org