🍷 Blood Alcohol (BAC) Calculator

Estimate blood alcohol content from drinks, weight and time.

Sex

Body weight (kg)

Standard drinks

Hours since first drink

—Estimated BAC

—Guidance

How it's calculated

Uses the Widmark formula: BAC = (grams of alcohol ÷ (body weight × distribution ratio)) − (0.015 × hours), where one standard drink ≈ 14 g of pure alcohol. This is a rough population estimate only — real BAC depends on food, metabolism, medication and more. Never use this to decide whether to drive. If you've been drinking, don't drive. Not medical or legal advice.