1. What is Blood Alcohol Content (BAC)?

Definition: BAC measures the percentage of alcohol in a person's bloodstream, used to determine legal intoxication levels.

Purpose: This calculator estimates BAC using the Widmark formula, which considers alcohol consumed, body weight, metabolism, and time.

2. How Does the BAC Calculator Work?

The calculator uses the Widmark formula:

Where:

• \( BAC \) — Blood Alcohol Content (%)
• \( A \) — Alcohol consumed (grams)
• \( W \) — Body weight (grams)
• \( r \) — Distribution ratio (0.68 for men, 0.55 for women)
• \( \beta \) — Alcohol elimination rate (%/hour)
• \( t \) — Time since consumption (hours)

Explanation: The formula calculates alcohol concentration in blood and subtracts metabolized alcohol over time.

3. Importance of BAC Calculation

Details: Understanding BAC helps assess impairment levels, with 0.08% being the legal limit for driving in most jurisdictions.

4. Using the Calculator

Tips: Enter alcohol consumed in grams, body weight in grams (1 lb ≈ 453.6 g), distribution ratio (default 0.68 for men), elimination rate (default 0.015%/hour), and time since drinking.

5. Frequently Asked Questions (FAQ)

Q1: How do I convert drinks to grams of alcohol?
A: Multiply standard drinks by 14 grams (US) or 10 grams (UK). 1 standard drink ≈ 14g pure alcohol.

Q2: Why different ratios for men and women?
A: Women generally have higher body fat percentage and less water content, leading to higher BAC.

Q3: What affects elimination rate?
A: Metabolism, liver health, food intake, and individual factors can change elimination rate (typically 0.015-0.020%/hour).

Q4: How accurate is this estimate?
A: It's an approximation. Actual BAC depends on many factors including food, medications, and individual metabolism.

Q5: What's the legal BAC limit?
A: Most US states use 0.08% for adults (21+), with lower limits for commercial drivers (0.04%) and zero tolerance for under 21.