How Long Until My Bac Is Zero Calculator

Understanding how long it takes for your Blood Alcohol Concentration (BAC) to return to zero is crucial for responsible drinking. Our calculator helps you estimate this time frame based on your BAC, weight, and gender.

1. Enter your BAC level.
2. Enter your weight in kilograms.
3. Select your gender.
4. Click ‘Calculate’.

The calculation is based on the Widmark formula: BAC = (A * W) / (R * V), where A is the alcohol consumed, W is body weight, R is the alcohol distribution ratio (0.7 for men, 0.6 for women), and V is the volume of total body water.

BAC Levels and Their Effects

BAC	Effects

Alcohol Consumption and BAC

Drinks	BAC (for a 70kg man)

• Always drink responsibly.
• Never drink and drive.
• Stay hydrated while drinking.

What factors affect how long it takes for my BAC to return to zero?

Factors include your weight, gender, alcohol consumption, and hydration level.

For more information, see the NIAAA’s definition of a standard drink and the WHO’s facts on alcohol.