Blood Alcohol Concentration Calculator

Widmark Formula:

\[ BAC = \frac{Alcohol\ consumed\ (g)}{Body\ weight\ (kg) \times r} \times 100 \]

Blood Alcohol Concentration (BAC):

Unit Converter ▲

Unit Converter ▼

From:	To:

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 and remains widely used for BAC estimation.

2. How Does the Calculator Work?

The calculator uses the Widmark formula:

\[ BAC = \frac{Alcohol\ consumed\ (g)}{Body\ weight\ (kg) \times r} \times 100 \]

Where:

\( Alcohol\ consumed \) — Total alcohol intake in grams
\( Body\ weight \) — Individual's body weight in kilograms
\( r \) — Widmark factor (0.68 for males, 0.55 for females)

Explanation: The formula accounts for alcohol distribution in body water, with different distribution factors for males and females 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 consumed in grams, body weight in kilograms, and select gender. All values must be valid (alcohol > 0, weight > 0). Note that this is an estimation and individual variations may occur.

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 reasonable estimate but doesn't account for individual metabolism, food intake, drinking duration, or other factors affecting alcohol absorption.

Q3: How do I convert drinks to grams of alcohol?
A: Standard drink contains approximately 14 grams of pure alcohol (e.g., 12 oz beer at 5%, 5 oz wine at 12%, 1.5 oz spirits at 40%).

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

Q5: What are the effects at different BAC levels?
A: 0.02-0.05%: Mild impairment; 0.05-0.08%: Significant impairment; 0.08-0.15%: Severe impairment; >0.30%: Risk of alcohol poisoning.