Blood Alcohol Content (BAC) is measured as grams of alcohol per 100 mL of blood. A BAC of 0.08% is the legal limit for driving in most US states.
Widmark Formula
BAC = (Alcohol in grams / (Body weight in grams × r)) − (0.015 × hours), where r = 0.68 for men, 0.55 for women.
Effects by BAC Level
- 0.02%: Mild relaxation, slight mood elevation
- 0.05%: Reduced inhibitions, impaired judgment
- 0.08%: Legal limit — poor coordination, slower reaction time
- 0.15%: Major impairment of balance and movement
- 0.30%+: Risk of loss of consciousness or death