Calculating BAC

Understanding Blood Alcohol Concentration

What is Blood Alcohol Concentration (BAC)?

Blood Alcohol Concentration, often abbreviated as BAC, measures the level of alcohol in your bloodstream. Knowing your BAC is crucial in situations like deciding whether it’s safe to drive after a night out or if you’re stopped by law enforcement for a suspected DUI (Driving Under the Influence). During a DUI stop, officers might ask you to perform field sobriety tests, such as balancing on one leg, following a light with your eyes, or walking a straight line heel-to-toe. If you fail these tests, they may suspect impairment due to alcohol or drugs and request further testing via breath, blood, or urine tests.

When alcohol enters your bloodstream, it raises your BAC. In the United States, including in Pennsylvania, the legal BAC limit for adults is typically 0.08 percent. Exceeding this limit can lead to a DUI charge. BAC tests quantify how much alcohol is in your blood; a BAC of 0.08 means there are 0.08 grams of alcohol per 100 milliliters of blood. For individuals under 21, Pennsylvania enforces a zero-tolerance policy for underage DUI, where any BAC of 0.02 percent or higher results in an automatic DUI charge.

Factors Influencing BAC

• Gender: Women generally reach higher BAC levels than men after consuming the same amount of alcohol, primarily due to smaller body sizes.
• Body Fat: People with more body fat may experience higher BAC since fat tissue does not absorb alcohol efficiently.
• Empty Stomach: Drinking without eating can result in a higher BAC, as food slows alcohol absorption, thus lowering BAC.
• Body Size: Smaller and lighter individuals tend to have higher BACs compared to larger individuals because of less body volume for alcohol distribution.

How to Determine Your BAC

Estimating your BAC requires understanding the alcohol content in different drinks. A “standard” drink equals a 5-ounce glass of wine, a 1.5-ounce shot of liquor, or a 12-ounce beer. Typically, wine ranges between 15-20% alcohol, liquor from 30-50%, and beer around 4-4.5%. A Long Island Iced Tea, which contains five types of alcohol, has an alcohol content of about 22%.

To calculate your BAC, consider factors like the session’s duration, total ounces of alcohol consumed, the alcoholic strength of the beverages, and your weight. Widmark’s Formula is often used for this purpose:

BAC = (The amount of alcohol in ounces multiplied by 5.14/ gender constant*weights in pounds ) – .015*the number of hours that have passed since you started drinking

• For the gender constant:
• Women use 0.66
• Men use 0.73

Example:

If a 150-pound woman drinks two 12-ounce beers over two hours:

% BAC = (1.20 x 5.14 / 150 x 0.66) – 0.015 x 2

% BAC = (6.168 / 99) – 0.03

% BAC = 0.062 – 0.03

% BAC = 0.032 (This is under the legal limit of 0.08% for adults, meaning you are not legally considered intoxicated.)

This is below the legal limit of 0.08% for adults, indicating no legal intoxication.

Steps to Take If Your BAC Is Too High

If requested to take a BAC test, comply with legal requirements, as refusal can lead to automatic license suspension and additional charges. If you are arrested for DUI, it’s essential to consult an experienced Kittanning DUI attorney immediately. At Logue Law Group, we offer expert counsel and have successfully managed numerous DUI cases across Kittanning, West Virginia, and Ohio. Contact us for a consultation at 844.PITT.DUI or visit our website for more details.