Estimate Your BAC Level
Estimate blood alcohol content from drinks, weight, time, and gender. Know when you are safe to drive.
How BAC Is Estimated
BAC = (Drinks × 0.6 oz alcohol × 5.14) ÷ (Weight × gender constant) - 0.015 × hours. The body metabolizes approximately 0.015 g/dL per hour regardless of size. A 170-lb male drinking 3 beers over 2 hours: BAC ≈ 0.053. This is an estimate — actual BAC varies with food, hydration, medications, and individual metabolism.
BAC Levels and Effects
0.02: Slight mood change. 0.05: Lowered inhibitions, impaired judgment. 0.08: Legal limit in all 50 states — significant impairment. 0.15: Major impairment of motor control. 0.30+: Risk of loss of consciousness. 0.40+: Potentially fatal. There is no safe level of BAC for driving — even 0.02 increases accident risk.
This calculator uses established formulas and industry standards to give you accurate, actionable results.