Drink Calculator

Blood Alcohol Content (BAC) Estimator

Use this calculator to get an estimated Blood Alcohol Content (BAC) based on your consumption, weight, gender, and time elapsed. Remember, this is an estimate and should not be used to determine fitness to drive or operate machinery.

(A standard drink contains approximately 14 grams of pure alcohol, e.g., 12 oz beer, 5 oz wine, 1.5 oz spirits)

function calculateBAC() { var numDrinks = parseFloat(document.getElementById('numDrinks').value); var bodyWeight = parseFloat(document.getElementById('bodyWeight').value); var genderMale = document.getElementById('genderMale').checked; var timeElapsed = parseFloat(document.getElementById('timeElapsed').value); var resultDiv = document.getElementById('bacResult'); // Input validation if (isNaN(numDrinks) || numDrinks < 0) { resultDiv.innerHTML = 'Please enter a valid number of drinks.'; return; } if (isNaN(bodyWeight) || bodyWeight <= 0) { resultDiv.innerHTML = 'Please enter a valid body weight.'; return; } if (isNaN(timeElapsed) || timeElapsed < 0) { resultDiv.innerHTML = 'Please enter a valid time elapsed.'; return; } // Constants for Widmark Formula (simplified) var alcoholGramsPerStandardDrink = 14; // Approximately 14 grams of pure alcohol var rFactor; // Distribution ratio if (genderMale) { rFactor = 0.68; // For men } else { rFactor = 0.55; // For women } var metabolismRate = 0.015; // Average BAC reduction per hour // Calculations var totalAlcoholGrams = numDrinks * alcoholGramsPerStandardDrink; var bodyWeightGrams = bodyWeight * 453.592; // Convert lbs to grams // Initial BAC calculation var initialBAC = (totalAlcoholGrams / (bodyWeightGrams * rFactor)) * 100; // Adjust for metabolism over time var metabolizedBAC = metabolismRate * timeElapsed; var finalBAC = initialBAC – metabolizedBAC; // Ensure BAC doesn't go below zero if (finalBAC = 0.08) { interpretation = 'Legal Impairment (0.08% and above): Significant impairment of motor skills, judgment, and reaction time. Driving is illegal and extremely dangerous.'; } else if (bacPercentage >= 0.05) { interpretation = 'Reduced Coordination (0.05% – 0.079%): Impaired judgment, reduced coordination, exaggerated behavior. Driving ability is significantly affected.'; } else if (bacPercentage >= 0.02) { interpretation = 'Mild Impairment (0.02% – 0.049%): Slight mood changes, relaxation, minor loss of judgment. Some effects on driving ability may be present.'; } else if (bacPercentage > 0) { interpretation = 'Very Low (0.001% – 0.019%): Minimal effects, if any.'; } else { interpretation = 'Sober (0.00%): No alcohol detected in the bloodstream.'; } resultDiv.innerHTML = '

Estimated BAC: ' + bacPercentage + '%

' + interpretation + 'This calculator provides an estimate only. Actual BAC can vary significantly due to individual differences, food intake, medication, and other factors. Do not rely on this calculator to make decisions about drinking and driving. Always drink responsibly.'; } .bac-calculator-container { font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif; background-color: #f9f9f9; border: 1px solid #ddd; padding: 25px; border-radius: 8px; max-width: 600px; margin: 20px auto; box-shadow: 0 4px 12px rgba(0, 0, 0, 0.08); } .bac-calculator-container h2 { color: #333; text-align: center; margin-bottom: 20px; font-size: 1.8em; } .bac-calculator-container p { color: #555; line-height: 1.6; margin-bottom: 15px; } .bac-input-group { margin-bottom: 18px; display: flex; flex-wrap: wrap; align-items: center; } .bac-input-group label { flex: 1 1 150px; font-weight: bold; color: #444; margin-right: 15px; } .bac-input-group input[type="number"] { flex: 2 1 200px; padding: 10px 12px; border: 1px solid #ccc; border-radius: 5px; font-size: 1em; box-sizing: border-box; max-width: 250px; } .bac-input-group input[type="radio"] { margin-right: 5px; margin-left: 15px; } .bac-input-group input[type="radio"] + label { font-weight: normal; flex: 0 0 auto; margin-right: 20px; } .bac-input-group .input-hint { flex-basis: 100%; font-size: 0.85em; color: #777; margin-top: 5px; margin-left: 165px; /* Align with input field */ } .bac-calculator-container button { display: block; width: 100%; padding: 12px 20px; background-color: #007bff; color: white; border: none; border-radius: 5px; font-size: 1.1em; cursor: pointer; transition: background-color 0.3s ease; margin-top: 20px; } .bac-calculator-container button:hover { background-color: #0056b3; } .bac-result { margin-top: 30px; padding: 20px; background-color: #e9f7ef; border: 1px solid #d4edda; border-radius: 8px; text-align: center; font-size: 1.1em; color: #333; } .bac-result h3 { color: #28a745; margin-top: 0; font-size: 1.6em; } .bac-result .error { color: #dc3545; font-weight: bold; } .bac-result .bac-warning { color: #dc3545; font-weight: bold; } .bac-result .bac-caution { color: #ffc107; font-weight: bold; } .bac-result .bac-mild { color: #17a2b8; } .bac-result .bac-low { color: #6c757d; } .bac-result .bac-sober { color: #28a745; } .bac-result .disclaimer { font-size: 0.85em; color: #777; margin-top: 15px; }

Understanding Your Blood Alcohol Content (BAC)

Blood Alcohol Content (BAC) is a measure of the amount of alcohol in your blood, expressed as a percentage. It's a critical indicator of intoxication and is used legally to define impairment, especially concerning driving. Even small amounts of alcohol can affect your judgment, coordination, and reaction time.

How is BAC Calculated?

The calculator above uses a simplified version of the Widmark formula, a widely recognized method for estimating BAC. Several factors influence your BAC:

• Number of Drinks: More alcohol consumed directly leads to a higher BAC. A "standard drink" is defined as containing approximately 14 grams of pure alcohol (e.g., 12 oz of 5% beer, 5 oz of 12% wine, or 1.5 oz of 40% spirits).
• Body Weight: Individuals with higher body weight generally have more body water, which dilutes the alcohol, leading to a lower BAC for the same amount of alcohol consumed.
• Gender: Women typically have less body water and higher body fat percentages than men, meaning alcohol is less diluted in their bodies. They also tend to have lower levels of alcohol dehydrogenase, an enzyme that metabolizes alcohol, leading to higher BACs than men of the same weight who consume the same amount of alcohol.
• Time Elapsed: Your liver metabolizes alcohol at a relatively constant rate, typically around 0.015% BAC per hour. The longer the time since your first drink, the more alcohol your body has processed, and your BAC will decrease.
• Other Factors: Food intake (eating before or while drinking slows absorption), medication, fatigue, and individual metabolic rates can also affect BAC.

BAC Levels and Their Effects

Understanding what different BAC levels mean is crucial for responsible drinking:

• 0.02% – 0.049%: Mild relaxation, slight mood alteration, minor loss of judgment. Some effects on driving ability may begin.
• 0.05% – 0.079%: Reduced coordination, impaired judgment, exaggerated behavior, difficulty steering. Driving ability is significantly affected.
• 0.08% and above: This is the legal limit for driving in most U.S. states. Significant impairment of motor skills, judgment, and reaction time. Speech may be slurred, and balance is poor. Driving is illegal and extremely dangerous.
• 0.10% and above: Clear deterioration of reaction time and control, slurred speech, poor coordination.
• 0.15% and above: Gross impairment of physical control, blurred vision, significant loss of balance.

Example Calculation:

Let's consider a 180 lb male who consumes 3 standard drinks over a period of 2 hours.

1. Total Alcohol Consumed: 3 drinks * 14 grams/drink = 42 grams of alcohol.
2. Body Weight in Grams: 180 lbs * 453.592 grams/lb = 81,646.56 grams.
3. 'r' Factor (Male): 0.68
4. Initial BAC: (42 grams / (81,646.56 grams * 0.68)) * 100 = (42 / 55,519.66) * 100 ≈ 0.0756%
5. Metabolized Alcohol: 0.015% per hour * 2 hours = 0.03%
6. Estimated Final BAC: 0.0756% – 0.03% = 0.0456%

In this scenario, the estimated BAC would be approximately 0.046%, indicating reduced coordination and impaired judgment, making driving unsafe.

Important Disclaimer:

This BAC calculator provides an estimate only. It cannot account for all individual physiological differences, recent food intake, medication interactions, or other variables that affect alcohol absorption and metabolism. Never use this calculator to determine if you are fit to drive or operate machinery. The safest choice is always to designate a sober driver or arrange for alternative transportation if you plan to consume alcohol. Drink responsibly.