Blood Alcohol Content Measures Level of Impairment

blood alcohol content

In 2021, 13,384 people died in alcohol-impaired driving traffic deaths – that’s one person every 39 minutes and a 14% increase from 2020. Your level of impairment is measured by what is referred to as blood alcohol content, or BAC. Alcohol impairs thinking, reasoning and muscle coordination, all abilities needed to operate a vehicle safely. This FAQ covers, in general, some frequently asked questions.

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If you have been seriously injured in a car accident where the other driver was under the influence, contact the law office of Nash & Franciskato for a free, no-obligation review of your case.

Quick Facts

  • A person is considered legally intoxicated at a .08 BAC.
  • Alcohol is quickly absorbed and can be measured within 30 to 70 minutes after a person has had a drink.
  • A BAC of 0.10 means that an individual’s blood supply contains one part alcohol for every 1000 parts blood.
  • With a blood alcohol level of 0.10 or higher, a person is at risk for having a blackout.
  • Drivers with a .08 BAC level are approximately four times more likely to crash than those with a BAC of zero. Those with a .15 BAC are at least 12 times more likely to crash.
  • The only thing that will sober you up to a BAC of 0.0% is time. Drinking caffeine or taking a cold shower may make you feel more alert, but you are still impaired.

Blood Alcohol Content and Impaired Driving

What is a BAC?

Blood alcohol content, or BAC, is a measurement of the percentage of alcohol that’s in your bloodstream after you’ve been drinking. As your BAC increases, so does the level of alcohol-related impairment you will experience.

Does the type of alcohol (i.e., beer vs. wine) impact the BAC?

drinking alcohol BAC blood alcohol contentNo. A drink is a drink whether it is beer, wine, or hard liquor.

One Standard Drink

  • One 12 oz. regular beer (4.5-6% alcohol)
  • One 5 oz. glass of wine (12% alcohol)
  • One 1.5 oz. shot of hard liquor (40% alcohol)

More Than One Standard Drink

  • One 16 oz. cup of beer = 1.4 drinks
  • One 40 oz. beer = 3.6 drinks
  • One 12 oz. glass of wine = 2.9 drinks
  • One 12 oz. margarita = 2–4 drinks, depending on ingredients

What factors can affect the BAC?

How fast a BAC rises can vary based on a host of factors.

  • Number of standard drinks (i.e., the more you drink, the higher your BAC)
  • How fast you drink (i.e., BAC rises faster when drinks are consumed quickly vs over a longer period of time)
  • Gender and body weight
  • Food in your stomach (i.e., absorption will be slowed if you’ve eaten)
  • Medications and more

Questions? Call us at (877) 284-6600.

At what Blood Alcohol Content level is a person considered impaired? How will you know?

Alcohol steadily decreases your ability to drive a motor vehicle safely. Even a small amount of alcohol can affect the brain and your ability to drive; however, signs of impairment will present differently for each person.

At just a .02 BAC level, there is some loss of judgment, a decline in visual functions and a decline in the ability to perform two tasks at the same time.

At 0.0% there is no alcohol in your blood, you are sober.

At a .05 BAC level, it gets harder to focus your eyes, judgement is impaired, and you have a lowered alertness level. What this means when you are behind the wheel:

  • reduced coordination
  • reduced ability to track moving objects
  • reduced response to emergency driving situations.

level of impairment operate a vehicle safely blood alcohol contentAt a .08 BAC level — when you are considered legally intoxicated — muscle coordination is impacted, which includes speech, vision, reaction time and hearing; and judgment, reasoning and memory are also impaired. When behind the wheel, this means:

  • Critical driving tasks are significantly impaired (i.e., braking, steering)
  • Ability to handle several tasks at one time is significantly reduced
  • Ability to detect danger is severely reduced
  • Impaired judgement and perception, which can lead to speeding and erratic lane changing
  • Slower reaction time and a decrease in coordination

How can someone stay safe when he/she plans to have a few drinks?

The best advice is to plan for someone else to drive, not you. Never drive after you have been drinking.

  • Designate a sober driver
  • Use a taxi, Uber or other public transportation
  • Call a friend or family member
  • Always wear your seat belt – it’s your best defense against impaired drivers


Have you been seriously injured in a motor vehicle accident in which you suffered serious injuries due to the other driver being under the influence and legally drunk? Call Nash & Franciskato at (877) 284-6600. We have a successful track record of helping accident victims collect the compensation they deserve.

One of our experienced staff will speak with you personally and will provide you with a free, no-obligation review of your case.



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Editor’s Note: This post was originally published December 5, 2022. It was reviewed on December 19, 2023 and updated for content and accuracy. 

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