By Tedia Gamino

Blood alcohol concentration, or BAC, measures the percentage of alcohol that’s in your bloodstream. Nationally it’s illegal to drive with a BAC that’s 0.08 percent or higher. In Wisconsin, however, BAC limits are different, and can vary based on your age and record of any  driving under the influence convictions. 

Operating While Intoxicated Rules in Wisconsin

If you’re 21 or over, with no history of driving under the influence (DUI), it is illegal to operate a motor vehicle:

  • With a Blood/Breath Alcohol Concentration (BAC) of 0.08 or greater;
  • While under the influence of an intoxicant;
  • With a detectable amount of a restricted controlled substance in your blood; or
  • While under the influence of a controlled substance or any other drug.​

For drivers with three or more prior Operating While Intoxicated (OWI) convictions, the limit is lower.  If you have 3 or more prior DUIs, you, cannot operate a motor vehicle if your BAC is greater than 0.02.

Drivers under 21 years of age are required by law to maintain absolute sobriety.  If you’re underage, operating a motor vehicle with any amount of alcohol in your system is illegal.

How much alcohol can you drink and still be legal to drive?

Research shows that your liver can process approximately 0.6 oz. of pure alcohol per hour—that’s typically the average drink. Aside from how much you drink, and how quickly your liver processes it, these four important factors affect your BAC:

  1. Body weight
  2. Gender
  3. How much you’ve had to eat
  4. If you’re on meds

Let’s take a closer look at each BAC influencer.

#1. Body Weight

The thinner you are, the less water that’s in your system—the less your body is able to dilute the effects of alcohol. Also, the less muscle tissue you have the less your body is able to dilute alcohol, because muscle also contains water. So you have a greater chance of feeling intoxicated than someone else who’s had the same amount to drink, but has a higher body weight and muscle mass.

#2. Gender

Gender can have a significant impact on one’s BAC. When it comes to muscle and body fat, men and women have different percentages of each and this impacts their BAC levels because muscle contains more water than fat. Women’s bodies are also different in that they produce less of an enzyme called dehydrogenase, which breaks down alcohol.

#3. How Much You’ve Had to Eat

How much you eat influences your BAC. Food slows down the amount of alcohol that’s absorbed in your bloodstream, so if you drink on an empty stomach your body will absorb the alcohol faster and cause you to feel intoxicated quicker.

#4. If You’re on Medication

It’s never wise to mix medications with alcohol. Studies show that antidepressants, cough medicines, and other meds can intensify your body’s reaction to alcohol and cause your BAC to be higher than it would normally be.

Other Variables

Other factors influence your BAC, including:

  • How fast you drink
  • Your alcohol tolerance
  • The kind of alcohol you consume

Do You Need to Talk to an Attorney About an OWI, DWI, or a DUI charge?

If you’ve been charged with an OWI, DWI, or a DUI, call our office at 414-383-6700 to schedule a consultation with one of our experienced defense attorneys who can provide the guidance you need.

By Attorney Tedia Gamino