Blood Alcohol Content (BAC) Calculator

Widmark Formula:

\[ BAC = \left(\frac{\text{grams\_alcohol}}{\text{weight} \times r}\right) \times 100 \]

Alcohol Consumed:

grams

Body Weight:

Gender:

Hours Since Drinking:

hours

Estimated Blood Alcohol Content (BAC):

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1. What is Blood Alcohol Content?

Blood Alcohol Content (BAC) is a measure of the amount of alcohol present in a person's bloodstream. It's expressed as a percentage of alcohol in the blood (e.g., 0.08% means 0.08 grams of alcohol per 100 ml of blood). BAC is used to assess intoxication levels and determine legal limits for driving.

2. How Does the Calculator Work?

The calculator uses the Widmark formula:

\[ BAC = \left(\frac{\text{grams\_alcohol}}{\text{weight} \times r}\right) \times 100 \]

Where:

\( grams\_alcohol \) — Total alcohol consumed in grams
\( weight \) — Body weight in kilograms
\( r \) — Distribution ratio (0.68 for men, 0.55 for women)

Explanation: The formula accounts for alcohol distribution in body water. The calculation also subtracts 0.015% per hour for alcohol metabolism.

3. Understanding BAC Levels

Typical Effects:

0.02-0.03%: Mild euphoria, slight relaxation
0.05-0.06%: Reduced inhibitions, exaggerated behavior
0.08-0.10%: Impaired coordination, legal intoxication in most countries
0.20%: Confusion, disorientation, nausea
0.30%: Possible loss of consciousness
0.40%+: Potentially fatal

4. Using the Calculator

Tips:

Convert drinks to grams of alcohol (1 standard drink ≈ 14g alcohol in US)
Use actual body weight, not ideal weight
Account for time since first drink
Remember this is only an estimate - many factors affect actual BAC

5. Frequently Asked Questions (FAQ)

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

Q2: What's the legal BAC limit for driving?
A: In most US states it's 0.08%, but lower for commercial drivers (0.04%) and under 21 (0.01-0.02%).

Q3: How long does alcohol stay in your system?
A: The liver metabolizes about 1 standard drink per hour (0.015% BAC per hour).

Q4: Can I sober up quickly with coffee or cold showers?
A: No. Only time can reduce BAC. These methods might make you feel more alert but don't lower BAC.

Q5: Why is the distribution ratio different for women?
A: Women typically have higher body fat percentage and less body water, leading to higher BAC from the same amount of alcohol.