Blood Alcohol Content (BAC) Estimator
Enter the number of standard drinks, your body weight, biological sex, and hours elapsed since you started drinking to get an approximate BAC estimate. This is an educational estimate only, not a substitute for professional judgment.
About this calculator
Estimate your approximate blood alcohol content based on drinks consumed, body weight, gender, and time elapsed since drinking began.
Frequently Asked Questions
How accurate is this estimate?
This calculator provides a rough approximation using the Widmark formula. Actual BAC varies by metabolism, food intake, medications, and other individual factors. Never use this to decide whether it's safe to drive.
What counts as a standard drink?
A standard drink is typically 12 oz of beer, 5 oz of wine, or 1.5 oz of distilled spirits, each containing roughly 0.6 oz of pure alcohol.
Why does biological sex matter?
Body water percentage differs on average between men and women, affecting how alcohol is distributed and diluted in the body, which the Widmark formula accounts for with different constants.