Blood Alcohol Calculator
Estimate your Blood Alcohol Content (BAC) based on gender, weight, number of drinks, type of alcohol, and time elapsed. Understand your intoxication level and get safety recommendations.
Published by:
isCalculator Editorial Team
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How to use this tool?
How to Use the Blood Alcohol Calculator
- Select your gender – Choose Male or Female from the dropdown. This adjusts the Widmark factor used in the calculation.
- Enter your weight – Input your weight in kilograms (kg). Must be between 30 and 300 kg.
- Enter the number of drinks – A whole number between 0 and 50.
- Choose the alcohol type – Select Beer (5%), Wine (12%), or Spirits (40%). Each has a standard serving size.
- Enter time since first drink – In hours (use decimals for half hours, e.g., 2.5). Range: 0 to 24.
- Click "Calculate BAC" – Your result appears below with your BAC percentage, a category description, and the formula used.
Note: All inputs are metric (kg, hours). The calculator uses the Widmark formula and accounts for alcohol metabolism (0.015% per hour). A BAC of 0.08% is often the legal limit for driving.
Previous Results
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Frequently Asked Questions
This calculator provides an estimate using the Widmark formula. Actual BAC can vary based on metabolism, food intake, and other factors. It should not be used to determine if it is safe to drive.
In many countries, the legal limit is 0.08% for drivers over 21. However, limits vary by jurisdiction. Always check local laws.
Women generally have a higher BAC than men after consuming the same amount of alcohol due to differences in body composition and water volume. The Widmark factor accounts for this.
