#bmi-calculator-container {
font-family: sans-serif;
border: 1px solid #ccc;
padding: 20px;
border-radius: 8px;
max-width: 400px;
margin: 20px auto;
background-color: #f9f9f9;
}
#bmi-calculator-inputs .form-group {
margin-bottom: 15px;
}
#bmi-calculator-inputs label {
display: block;
margin-bottom: 5px;
font-weight: bold;
}
#bmi-calculator-inputs input[type="number"] {
width: calc(100% – 12px);
padding: 8px;
border: 1px solid #ccc;
border-radius: 4px;
}
#bmi-calculator-inputs button {
background-color: #4CAF50;
color: white;
padding: 10px 15px;
border: none;
border-radius: 4px;
cursor: pointer;
font-size: 16px;
}
#bmi-calculator-inputs button:hover {
background-color: #45a049;
}
#bmi-result {
margin-top: 20px;
text-align: center;
}
#bmi-result h3 {
margin-bottom: 10px;
color: #333;
}
#bmiValue {
font-size: 2em;
font-weight: bold;
color: #007bff;
}
#bmiCategory {
font-style: italic;
color: #666;
}
function calculateBMI() {
var weightInput = document.getElementById("weight");
var heightInput = document.getElementById("height");
var bmiValueSpan = document.getElementById("bmiValue");
var bmiCategoryPara = document.getElementById("bmiCategory");
var weight = parseFloat(weightInput.value);
var height = parseFloat(heightInput.value);
if (isNaN(weight) || isNaN(height) || height <= 0) {
bmiValueSpan.textContent = "Invalid Input";
bmiCategoryPara.textContent = "";
return;
}
var bmi = weight / (height * height);
bmi = bmi.toFixed(1); // Round to one decimal place
bmiValueSpan.textContent = bmi;
var category = "";
if (bmi = 18.5 && bmi = 25 && bmi <= 29.9) {
category = "Overweight";
} else {
category = "Obesity";
}
bmiCategoryPara.textContent = "Category: " + category;
}
Understanding Body Mass Index (BMI)
Body Mass Index (BMI) is a simple calculation using a person's height and weight. The formula is derived from the mass and height of a person. BMI can be a useful tool to broadly gauge whether an individual has a healthy weight for their height. In adults, a higher BMI can indicate high body fatness.
How BMI is Calculated
The formula for BMI is:
BMI = weight (kg) / [height (m)]2
Where:
- weight is measured in kilograms (kg).
- height is measured in meters (m).
For example, if a person weighs 70 kg and is 1.75 meters tall:
BMI = 70 / (1.75 * 1.75) = 70 / 3.0625 = 22.86
This calculated BMI of 22.86 would typically fall into the "Normal weight" category.
BMI Categories
The following categories are generally used by healthcare professionals:
- Underweight: BMI less than 18.5
- Normal weight: BMI between 18.5 and 24.9
- Overweight: BMI between 25 and 29.9
- Obesity: BMI 30 or greater
Important Considerations
While BMI is a useful screening tool, it has limitations. It does not distinguish between muscle mass and fat mass. Therefore, a very muscular individual might have a high BMI but still be healthy. Similarly, BMI does not account for body composition or fat distribution. It is always recommended to consult with a healthcare professional for a comprehensive assessment of your health and weight status.