.bac-calculator-container {
font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
max-width: 700px;
margin: 20px auto;
padding: 25px;
border: 1px solid #e0e0e0;
border-radius: 10px;
background-color: #f9f9f9;
box-shadow: 0 4px 12px rgba(0, 0, 0, 0.08);
}
.bac-calculator-container h2 {
color: #2c3e50;
text-align: center;
margin-bottom: 25px;
font-size: 1.8em;
}
.bac-calculator-container .input-group {
margin-bottom: 18px;
display: flex;
flex-direction: column;
}
.bac-calculator-container label {
display: block;
margin-bottom: 8px;
color: #34495e;
font-weight: bold;
font-size: 0.95em;
}
.bac-calculator-container input[type="number"],
.bac-calculator-container select {
width: calc(100% – 22px);
padding: 12px;
border: 1px solid #ccc;
border-radius: 6px;
font-size: 1em;
box-sizing: border-box;
transition: border-color 0.3s ease;
}
.bac-calculator-container input[type="number"]:focus,
.bac-calculator-container select:focus {
border-color: #007bff;
outline: none;
box-shadow: 0 0 0 3px rgba(0, 123, 255, 0.25);
}
.bac-calculator-container .radio-group {
display: flex;
gap: 20px;
margin-top: 5px;
}
.bac-calculator-container .radio-group label {
font-weight: normal;
display: flex;
align-items: center;
cursor: pointer;
}
.bac-calculator-container .radio-group input[type="radio"] {
margin-right: 8px;
transform: scale(1.2);
}
.bac-calculator-container button {
width: 100%;
padding: 14px;
background-color: #007bff;
color: white;
border: none;
border-radius: 6px;
font-size: 1.1em;
font-weight: bold;
cursor: pointer;
transition: background-color 0.3s ease, transform 0.2s ease;
margin-top: 20px;
}
.bac-calculator-container button:hover {
background-color: #0056b3;
transform: translateY(-2px);
}
.bac-calculator-container #bacResult {
margin-top: 25px;
padding: 15px;
border-radius: 6px;
background-color: #e9f7ef;
border: 1px solid #d4edda;
color: #155724;
font-size: 1.2em;
text-align: center;
font-weight: bold;
min-height: 30px;
display: flex;
align-items: center;
justify-content: center;
}
.bac-calculator-container #bacResult.error {
background-color: #f8d7da;
border-color: #f5c6cb;
color: #721c24;
}
.bac-calculator-container .disclaimer {
margin-top: 25px;
font-size: 0.85em;
color: #6c757d;
text-align: center;
line-height: 1.5;
}
.bac-calculator-container .article-content {
margin-top: 40px;
line-height: 1.7;
color: #333;
font-size: 1em;
}
.bac-calculator-container .article-content h3 {
color: #2c3e50;
margin-top: 25px;
margin-bottom: 15px;
font-size: 1.5em;
}
.bac-calculator-container .article-content p {
margin-bottom: 15px;
}
.bac-calculator-container .article-content ul {
list-style-type: disc;
margin-left: 25px;
margin-bottom: 15px;
}
.bac-calculator-container .article-content li {
margin-bottom: 8px;
}
function calculateBAC() {
var numDrinks = parseFloat(document.getElementById("numDrinks").value);
var drinkOz = parseFloat(document.getElementById("drinkOz").value);
var drinkABV = parseFloat(document.getElementById("drinkABV").value);
var bodyWeightLbs = parseFloat(document.getElementById("bodyWeightLbs").value);
var genderMale = document.getElementById("genderMale").checked;
var timeHours = parseFloat(document.getElementById("timeHours").value);
var bacResultDiv = document.getElementById("bacResult");
// Clear previous results and error states
bacResultDiv.innerHTML = "";
bacResultDiv.classList.remove("error");
// Input validation
if (isNaN(numDrinks) || numDrinks < 0 ||
isNaN(drinkOz) || drinkOz <= 0 ||
isNaN(drinkABV) || drinkABV 100 ||
isNaN(bodyWeightLbs) || bodyWeightLbs <= 0 ||
isNaN(timeHours) || timeHours < 0) {
bacResultDiv.innerHTML = "Please enter valid positive numbers for all fields.";
bacResultDiv.classList.add("error");
return;
}
// Constants
var specificGravityEthanol = 0.789; // g/mL
var flOzToMl = 29.5735; // 1 fl oz = 29.5735 mL
var lbsToGrams = 453.592; // 1 lb = 453.592 grams
var alcoholEliminationRate = 0.015; // % per hour
// Determine 'r' factor based on gender
var rFactor;
if (genderMale) {
rFactor = 0.73; // For men
} else {
rFactor = 0.66; // For women
}
// 1. Calculate total grams of pure alcohol consumed
var alcoholPerDrinkMl = drinkOz * flOzToMl * (drinkABV / 100);
var alcoholPerDrinkGrams = alcoholPerDrinkMl * specificGravityEthanol;
var totalAlcoholGrams = numDrinks * alcoholPerDrinkGrams;
// 2. Convert body weight to grams
var bodyWeightGrams = bodyWeightLbs * lbsToGrams;
// 3. Calculate initial BAC using Widmark formula
// BAC = (Total grams of alcohol / (Body weight in grams * r)) * 100
var initialBAC = (totalAlcoholGrams / (bodyWeightGrams * rFactor)) * 100;
// 4. Adjust BAC for time elapsed
var bacReduction = timeHours * alcoholEliminationRate;
var finalBAC = initialBAC – bacReduction;
// Ensure BAC doesn't go below zero
if (finalBAC < 0) {
finalBAC = 0;
}
// Display result
bacResultDiv.innerHTML = "Estimated BAC: " + finalBAC.toFixed(3) + "%";
}
Blood Alcohol Content (BAC) Level Calculator
Disclaimer: This BAC calculator provides an estimate based on average physiological responses and the Widmark formula. It should not be used to determine fitness to drive or operate machinery. Individual results can vary significantly due to metabolism, food intake, medication, and other factors. Always err on the side of caution.
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. For example, a BAC of 0.08% means there are 0.08 grams of alcohol for every 100 milliliters of blood. This metric is crucial for understanding the level of intoxication and is often used as a legal standard for driving impairment.
How BAC is Calculated
The most widely accepted method for estimating BAC is the Widmark formula, which takes into account several key factors:
- Total Alcohol Consumed: The more alcohol you drink, the higher your BAC will be. This is calculated based on the number of drinks, their volume, and their alcohol by volume (ABV) percentage.
- Body Weight: A heavier person generally has more body water, which dilutes the alcohol, leading to a lower BAC for the same amount of alcohol consumed compared to a lighter person.
- Gender: Women typically have a higher body fat percentage and less body water than men, meaning alcohol is less diluted in their system. They also tend to have lower levels of alcohol dehydrogenase, an enzyme that metabolizes alcohol, leading to a higher BAC even if they weigh the same as a man. The 'r' factor in the Widmark formula accounts for this (approximately 0.73 for men and 0.66 for women).
- Time Elapsed: The liver metabolizes alcohol at a relatively constant rate, typically around 0.015% per hour. As time passes since your last drink, your BAC will decrease.
Other factors like food intake, medication, fatigue, and individual metabolism can also influence BAC, but are not typically included in simplified calculator models.
What is a "Standard Drink"?
In the United States, a "standard drink" contains approximately 0.6 fluid ounces or 14 grams of pure alcohol. This amount is typically found in:
- 12 ounces of regular beer (about 5% ABV)
- 5 ounces of wine (about 12% ABV)
- 1.5 ounces of distilled spirits (about 40% ABV or 80 proof)
It's important to note that many craft beers, wines, and mixed drinks can have significantly higher alcohol content than these standard definitions.
BAC Levels and Their Effects
- 0.02% – 0.03%: Mild relaxation, slight body warmth, altered mood.
- 0.05% – 0.06%: Impaired judgment, lowered inhibitions, reduced coordination, exaggerated behavior. Legal limit for driving in some countries.
- 0.08%: Impaired muscle coordination, speech, vision, reaction time, and judgment. This is the legal limit for driving under the influence (DUI) in most U.S. states.
- 0.10% – 0.12%: Significant impairment of motor coordination and loss of judgment. Slurred speech.
- 0.15%: Gross impairment of motor control, blurred vision, major loss of balance.
- 0.20% – 0.29%: Nausea, vomiting, severe motor impairment, memory blackouts.
- 0.30% – 0.39%: Potential for loss of consciousness, significant risk of alcohol poisoning.
- 0.40% and above: High risk of coma, respiratory arrest, and death.
Safety and Responsibility
Knowing your estimated BAC can help you make more informed decisions about alcohol consumption. However, this calculator is for educational purposes only and should not be relied upon for personal safety or legal judgments. If you plan to drink, always arrange for a designated driver, use public transportation, or call a ride-sharing service. Never drink and drive.