Ideal BMI Calculator
body {
font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
background-color: #f8f9fa;
color: #333;
line-height: 1.6;
margin: 0;
padding: 20px;
}
.bmi-calc-container {
max-width: 700px;
margin: 40px auto;
background-color: #ffffff;
padding: 30px;
border-radius: 8px;
box-shadow: 0 4px 15px rgba(0, 0, 0, 0.1);
border: 1px solid #e0e0e0;
}
h1, h2 {
color: #004a99;
text-align: center;
margin-bottom: 20px;
}
.input-group {
margin-bottom: 20px;
display: flex;
align-items: center;
flex-wrap: wrap;
}
.input-group label {
flex: 1 1 150px; /* Allows labels to take up space but not grow indefinitely */
margin-right: 15px;
font-weight: 500;
color: #004a99;
text-align: right;
}
.input-group input[type="number"] {
flex: 2 1 200px; /* Allows inputs to grow and take more space */
padding: 10px 12px;
border: 1px solid #ccc;
border-radius: 4px;
font-size: 1rem;
box-sizing: border-box; /* Include padding and border in the element's total width and height */
}
.input-group input[type="number"]:focus {
border-color: #004a99;
outline: none;
box-shadow: 0 0 0 2px rgba(0, 74, 153, 0.2);
}
button {
display: block;
width: 100%;
padding: 12px 20px;
background-color: #004a99;
color: white;
border: none;
border-radius: 4px;
font-size: 1.1rem;
cursor: pointer;
transition: background-color 0.3s ease;
margin-top: 10px;
}
button:hover {
background-color: #003366;
}
#result {
margin-top: 30px;
padding: 20px;
background-color: #e7f3ff;
border-left: 5px solid #004a99;
text-align: center;
font-size: 1.4rem;
font-weight: bold;
color: #004a99;
border-radius: 5px;
}
#result .bmi-category {
font-size: 1.1rem;
font-weight: normal;
margin-top: 8px;
color: #333;
}
.article-content {
margin-top: 40px;
padding: 25px;
background-color: #ffffff;
border-radius: 8px;
box-shadow: 0 2px 10px rgba(0, 0, 0, 0.05);
border: 1px solid #e0e0e0;
}
.article-content h2 {
text-align: left;
color: #004a99;
margin-bottom: 15px;
}
.article-content p, .article-content ul {
margin-bottom: 15px;
}
.article-content ul {
padding-left: 20px;
}
.article-content li {
margin-bottom: 8px;
}
.article-content strong {
color: #004a99;
}
@media (max-width: 600px) {
.input-group {
flex-direction: column;
align-items: stretch;
}
.input-group label {
text-align: left;
margin-bottom: 5px;
margin-right: 0;
}
.input-group input[type="number"] {
width: 100%;
flex: none;
}
.bmi-calc-container {
padding: 20px;
}
h1 {
font-size: 1.8rem;
}
#result {
font-size: 1.2rem;
}
}
Understanding Your Body Mass Index (BMI)
Body Mass Index (BMI) is a measure used to estimate the amount of body fat a person has based on their height and weight. It's a widely recognized screening tool that can help identify potential weight categories that may lead to health problems. While it's not a direct measure of body fat or an individual's health status, it provides a useful starting point for assessing weight relative to height.
How BMI is Calculated
The formula for BMI is straightforward:
BMI = Weight (kg) / [Height (m)]²
Alternatively, if your height is in centimeters, you first convert it to meters by dividing by 100. For instance, 175 cm becomes 1.75 meters.
Using the calculator above simplifies this process. You enter your weight in kilograms and your height in centimeters, and the calculator automatically performs the necessary conversion and calculation.
BMI Categories and Health Implications
The calculated BMI value is then compared against a standard range to determine a weight category. These categories are generally defined as follows:
- Underweight: BMI less than 18.5
- Normal weight: BMI between 18.5 and 24.9
- Overweight: BMI between 25.0 and 29.9
- Obesity Class I: BMI between 30.0 and 34.9
- Obesity Class II: BMI between 35.0 and 39.9
- Obesity Class III (Severe Obesity): BMI 40.0 and above
Being in the underweight or overweight/obesity categories can increase the risk of various health issues. For example, being underweight can be associated with nutritional deficiencies, weakened immunity, and osteoporosis. Conversely, being overweight or obese is linked to an increased risk of heart disease, type 2 diabetes, high blood pressure, certain cancers, and sleep apnea.
Important Considerations
It's crucial to remember that BMI is a general guide and has limitations. It does not account for factors such as:
- Muscle mass: Very muscular individuals may have a high BMI without having excess body fat.
- Body composition: Two people with the same BMI can have different amounts of body fat and muscle.
- Age and Sex: BMI interpretations can vary slightly for different age groups and sexes.
- Ethnicity: Certain ethnic groups may have different health risks at specific BMI levels.
Therefore, your BMI should be discussed with a healthcare professional who can consider your overall health, lifestyle, and individual circumstances to provide personalized advice. This calculator is intended for informational purposes only and should not substitute professional medical advice.
function calculateBMI() {
var weightInput = document.getElementById("weight");
var heightInput = document.getElementById("height");
var resultDiv = document.getElementById("result");
var weight = parseFloat(weightInput.value);
var heightCm = parseFloat(heightInput.value);
// Basic input validation
if (isNaN(weight) || isNaN(heightCm) || weight <= 0 || heightCm <= 0) {
resultDiv.innerHTML = "Please enter valid positive numbers for weight and height.";
resultDiv.style.color = "#dc3545"; // Red for error
return;
}
// Convert height from cm to meters
var heightM = heightCm / 100;
// Calculate BMI
var bmi = weight / (heightM * heightM);
// Round BMI to two decimal places
var bmiRounded = bmi.toFixed(2);
var bmiCategory = "";
var categoryColor = "#28a745"; // Default to green for normal
if (bmi = 18.5 && bmi = 25 && bmi <= 29.9) {
bmiCategory = "Overweight";
categoryColor = "#fd7e14"; // Orange for overweight
} else {
bmiCategory = "Obese";
categoryColor = "#dc3545"; // Red for obese
}
resultDiv.innerHTML = "Your BMI is:
" + bmiRounded + "Category: " + bmiCategory + "";
resultDiv.style.backgroundColor = "#e7f3ff"; // Reset background color
resultDiv.style.borderColor = categoryColor; // Use color to indicate category
resultDiv.style.borderLeftWidth = "5px";
resultDiv.style.borderLeftStyle = "solid";
}