Blood Alcohol Calculator (BAC) - Widmark Formula & Sobriety Time

Estimate blood alcohol concentration (BAC %) and exact hours until legal driving limit (0.08% BAC) and full sobriety (0.00%) using the clinical Widmark equation.

⚙️ Configuration & Inputs

Biological Gender

Body Weight (lbs)

Standard Drinks Consumed 1 drink = 12 oz beer (5%), 5 oz wine (12%), or 1.5 oz spirit (40%)

Hours Since First Drink

📊 Results & Analysis

Estimated Current BAC 0.046% Below US Legal Limit (0.08%)

Hours Until 0.00% (Fully Sober) 3.1 Hours Liver metabolism: ~0.015% per hour

Hours Until Legal to Drive (0.08%) 0.0 Hours Already under 0.08%

Physical Effects Mild Euphoria Relaxation, minor reduction in alertness

The Widmark Blood Alcohol Equation

The Swedish chemist E.M.P. Widmark developed the definitive formula relating alcohol consumption to blood concentration:

BAC = [Alcohol in grams / (Weight in grams × r)] × 100 - (Beta × Hours)

Disclaimer: This tool provides general estimates only. Never drink and drive.

Frequently Asked Questions

No. The human liver metabolizes alcohol at a constant physiological rate of roughly 0.015% BAC per hour. Caffeine may make you feel more awake, but your BAC remains identical.

In all 50 states, the legal limit for non-commercial drivers age 21+ is 0.08% BAC (0.05% in Utah).