1. What is the Widmark Formula?

The Widmark formula is a mathematical equation used to estimate blood alcohol concentration (BAC) based on the amount of alcohol consumed, body weight, and gender. It was developed by Swedish professor Erik M. P. Widmark in the 1930s.

2. How Does the Calculator Work?

The calculator uses the Widmark formula:

Where:

• \( Alcohol\ g \) — Total alcohol consumed in grams
• \( Body\ Weight\ kg \) — Body weight in kilograms
• \( r \) — Widmark factor (0.68 for men, 0.55 for women)

Explanation: The formula estimates the distribution of alcohol in body water, with different distribution factors for men and women due to differences in body composition.

3. Importance of BAC Calculation

Details: BAC estimation is crucial for understanding alcohol impairment levels, legal limits for driving, and making informed decisions about alcohol consumption and safety.

4. Using the Calculator

Tips: Enter alcohol consumption in grams (1 standard drink ≈ 14g pure alcohol), body weight in kilograms, and select gender. All values must be valid positive numbers.

5. Frequently Asked Questions (FAQ)

Q1: What is the legal BAC limit for driving?
A: Legal limits vary by country, but typically range from 0.05% to 0.08%. Some regions have zero tolerance policies.

Q2: How accurate is the Widmark formula?
A: It provides a theoretical estimate. Actual BAC can vary due to metabolism rate, food consumption, medication, and individual differences.

Q3: How do I convert drinks to grams of alcohol?
A: Standard drink conversions: Beer (5% ABV, 350ml) ≈ 14g, Wine (12% ABV, 150ml) ≈ 14g, Spirits (40% ABV, 45ml) ≈ 14g.

Q4: Why different r values for men and women?
A: Women typically have higher body fat percentage and lower water content, leading to higher BAC from the same alcohol amount.

Q5: How long does it take for alcohol to leave the system?
A: Average metabolism rate is about 0.015% BAC per hour, but this varies by individual and other factors.