Blood Alcohol Content (BAC) Calculator
Estimate your blood alcohol level based on drinks consumed, body weight, gender, and time elapsed. This is an estimate only and should not be used to determine fitness to drive.
Disclaimer: This calculator provides estimates only. Actual BAC depends on many factors including food consumption, medications, liver function, and tolerance. Never drive after drinking. If you are concerned about your drinking, take our free screening quiz or call SAMHSA at 1-800-662-4357.
What is BAC?
Blood Alcohol Content measures the percentage of alcohol in your bloodstream. A BAC of 0.08% is the legal driving limit in all US states. Even lower BAC levels impair judgment and reaction time.
BAC levels and effects
0.02-0.03%: Mild relaxation. 0.04-0.06%: Lowered inhibitions, impaired judgment. 0.08%: Legal limit, significant impairment. 0.10-0.15%: Obvious intoxication, slurred speech. 0.20%+: Confusion, nausea, risk of blackout. 0.30%+: Medical emergency. 0.40%+: Risk of death.
What is a standard drink?
12 oz beer (5% ABV). 5 oz wine (12% ABV). 1.5 oz liquor (40% ABV). Many drinks exceed these standard sizes.