Blood Alcohol Content (BAC) Calculator

The Widmark formula estimates BAC as (grams of alcohol consumed ÷ (body weight in grams × distribution ratio)) × 100, minus an elimination term for time elapsed (roughly 0.015% BAC metabolized per hour) — it's the standard educational approximation used in alcohol-education contexts, though real BAC varies with food intake, metabolism, and other individual factors.

The Widmark distribution ratio (r) reflects how alcohol distributes through body water — commonly cited values are about 0.68 for males and 0.55 for females, since body composition differences (average body water percentage) affect how concentrated the same amount of alcohol becomes in the bloodstream.

A U.S. standard drink contains about 14 grams of pure alcohol — roughly a 12 oz regular beer (5% ABV), a 5 oz glass of wine (12% ABV), or a 1.5 oz shot of 80-proof spirits (40% ABV). Stronger or larger pours contain more alcohol than a single standard drink.

No — this is an educational estimate only, not a precise or legally reliable measurement. Actual BAC is affected by food intake, hydration, medications, individual metabolism, and drink strength in ways this simplified formula can't fully capture. Never use any online calculator to decide whether it's safe to drive — if you've been drinking, don't drive.