BAC Calculator & DUI Estimator
Estimate your Blood Alcohol Content (BAC) instantly using the Widmark Formula based on your weight, gender, and consumption.
Understanding Blood Alcohol Content (BAC)
Your BAC measures the percentage of alcohol in your bloodstream. In the United States, the magic number is 0.08%. If you are caught driving at or above this level, you can be charged with Driving Under the Influence (DUI) or Driving While Intoxicated (DWI), leading to license suspension, heavy fines, and even jail time.
This calculator uses the “Widmark Formula,” which is the standard used by forensic scientists. It calculates BAC by dividing total alcohol grams by body weight (adjusted for gender) and then subtracting alcohol eliminated over time (metabolism rate).
Factors That Affect Your BAC
- Gender: Men typically have more body water and an enzyme that breaks down alcohol faster than women.
- Weight: A heavier person has more blood volume to dilute the alcohol.
- Time: The only thing that lowers BAC is time. The body eliminates roughly 0.015% BAC per hour.
- Stomach Content: Drinking on an empty stomach causes alcohol to absorb much faster.
Frequently Asked Questions
How many drinks gets you to 0.08%?
It varies, but for an average 180lb male, it takes about 4 standard drinks in one hour. For a 140lb female, it may only take 2-3 drinks.
Can I drive if my BAC is 0.05%?
Legally, yes (in most states except Utah, where the limit is 0.05%). However, “buzzed driving” is still dangerous, and police can still charge you with impairment if you fail a field sobriety test, even if you blow under 0.08%.
Does drinking coffee lower my BAC?
No. Coffee might make you feel more awake, but it does not remove alcohol from your blood. Only time (liver function) can lower your BAC.