1. What is a BAC Calculator?

Definition: This calculator estimates Blood Alcohol Concentration (BAC) using the Widmark formula, which considers alcohol consumed, body weight, gender, time, and elimination rate.

Purpose: It helps individuals estimate their blood alcohol level for responsible drinking awareness and safety planning.

2. How Does the Calculator Work?

The calculator uses the Widmark formula:

Where:

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

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

3. Importance of BAC Calculation

Details: Understanding BAC helps prevent impaired driving, alcohol poisoning, and promotes safer drinking habits by estimating intoxication levels.

4. Using the Calculator

Tips: Enter alcohol consumed in grams, body weight in grams, select gender, time since drinking, and elimination rate (default 0.015). All values must be ≥ 0.

5. Frequently Asked Questions (FAQ)

Q1: How do I convert drinks to grams of alcohol?
A: Multiply standard drinks by 14 (US) or 10 (UK) grams per drink, or use alcohol volume × ABV × 0.789 (density of ethanol).

Q2: Why is the distribution ratio different by gender?
A: Women typically have higher body fat percentage and lower water content, affecting alcohol distribution.

Q3: Can BAC go below zero?
A: No, the calculator automatically sets any negative result to 0%.

Q4: How accurate is this calculator?
A: It provides estimates. Actual BAC varies with metabolism, food intake, medications, and individual differences.

Q5: What's the legal BAC limit for driving?
A: In most US states it's 0.08%, but can be lower (0.05% or 0.02%) in some jurisdictions or for commercial drivers.