1. What is BAC?

Blood Alcohol Concentration (BAC) is a measure of the amount of alcohol in your bloodstream. It's expressed as a percentage and is used to determine legal intoxication levels for driving and other activities.

2. How Does the Calculator Work?

The calculator uses the Widmark formula:

Where:

• \( A \) — Alcohol consumed in grams
• \( W \) — Body weight in grams
• \( r \) — Distribution ratio (0.68 for men, 0.55 for women)
• \( \beta \) — Elimination rate (typically 0.015%/hour)
• \( t \) — Time since drinking in hours

Explanation: The equation estimates how alcohol distributes in body water and accounts for ongoing metabolism.

3. Importance of BAC Calculation

Details: Knowing your estimated BAC helps make informed decisions about driving and alcohol consumption. In most US states, 0.08% is the legal limit for driving.

4. Using the Calculator

Tips: Enter alcohol consumed in grams (1 standard drink ≈ 14g), your weight in grams (1 lb ≈ 453.6g), and time since drinking. Default values are provided for distribution ratio and elimination rate.

5. Frequently Asked Questions (FAQ)

Q1: How accurate is this calculator?
A: It provides an estimate. Actual BAC can vary based on food intake, metabolism, medications, and individual differences.

Q2: What's a standard drink?
A: Approximately 14g alcohol: 12oz beer (5%), 5oz wine (12%), or 1.5oz liquor (40%).

Q3: How long does alcohol stay in your system?
A: Alcohol is metabolized at about 0.015% BAC per hour on average, but this varies by individual.

Q4: Why is the ratio different for women?
A: Women generally have higher body fat percentage and less body water, leading to higher BAC from the same amount of alcohol.

Q5: Can I drive if my BAC is below 0.08%?
A: Impairment begins at lower levels (0.02-0.05%). It's safest to not drive after drinking.