var currentUnit = 'imperial';
function switchBmiUnit(unit) {
currentUnit = unit;
var impDiv = document.getElementById('imperial-inputs');
var metDiv = document.getElementById('metric-inputs');
var impBtn = document.getElementById('btn-imperial');
var metBtn = document.getElementById('btn-metric');
if (unit === 'imperial') {
impDiv.style.display = 'block';
metDiv.style.display = 'none';
impBtn.style.backgroundColor = '#27ae60';
impBtn.style.color = 'white';
metBtn.style.backgroundColor = 'white';
metBtn.style.color = '#27ae60';
metBtn.style.border = '1px solid #27ae60';
} else {
impDiv.style.display = 'none';
metDiv.style.display = 'block';
metBtn.style.backgroundColor = '#27ae60';
metBtn.style.color = 'white';
impBtn.style.backgroundColor = 'white';
impBtn.style.color = '#27ae60';
impBtn.style.border = '1px solid #27ae60';
}
}
function calculateBMI() {
var bmi = 0;
var weight = 0;
var heightInches = 0;
if (currentUnit === 'imperial') {
var ft = parseFloat(document.getElementById('ht_ft').value) || 0;
var inch = parseFloat(document.getElementById('ht_in').value) || 0;
weight = parseFloat(document.getElementById('wt_lb').value) || 0;
if (weight > 0 && (ft > 0 || inch > 0)) {
heightInches = (ft * 12) + inch;
bmi = (weight / (heightInches * heightInches)) * 703;
}
} else {
var cm = parseFloat(document.getElementById('ht_cm').value) || 0;
weight = parseFloat(document.getElementById('wt_kg').value) || 0;
if (weight > 0 && cm > 0) {
var heightMeters = cm / 100;
bmi = weight / (heightMeters * heightMeters);
}
}
var resultBox = document.getElementById('bmi-result-box');
var valDisp = document.getElementById('bmi-value');
var catDisp = document.getElementById('bmi-category');
var descDisp = document.getElementById('bmi-description');
if (bmi > 0 && bmi < 100) {
resultBox.style.display = 'block';
valDisp.innerText = bmi.toFixed(1);
var cat = "";
var color = "";
var desc = "";
if (bmi = 18.5 && bmi = 25 && bmi < 30) {
cat = "Overweight";
color = "#f39c12";
desc = "Your BMI is slightly above the ideal range. This can increase the risk of developing certain health conditions like heart disease or diabetes.";
} else {
cat = "Obese";
color = "#e74c3c";
desc = "Your BMI indicates a high amount of body fat. We recommend consulting a medical professional for guidance on health management.";
}
catDisp.innerText = cat;
catDisp.style.color = color;
valDisp.style.color = color;
descDisp.innerText = desc;
} else {
alert("Please enter valid height and weight values.");
}
}
Understanding the Height and Weight (BMI) Ratio
The Body Mass Index (BMI) is a widely used screening tool that assesses the relationship between a person's weight and their height. While it does not measure body fat directly, research has shown that BMI correlates moderately well with more direct measures of body fatness.
Why Calculate Your Height and Weight Ratio?
Keeping track of your height-to-weight ratio is crucial for identifying potential health risks. High BMI scores can be an indicator of high body fatness, which may lead to metabolic issues, cardiovascular diseases, and joint strain. Conversely, a very low BMI can indicate nutritional deficiencies or underlying health issues.
Standard BMI Categories
Below 18.5: Underweight
18.5 – 24.9: Normal or Healthy Weight
25.0 – 29.9: Overweight
30.0 and Above: Obese
Real-World Examples
To better understand how these numbers translate to real life, consider these scenarios:
Example 1: Metric
Height: 175 cm
Weight: 70 kg BMI: 22.9 (Healthy)
While this calculator provides a useful starting point, it is important to note its limitations. BMI does not distinguish between muscle mass and fat mass. Therefore, highly muscular individuals (like athletes or bodybuilders) may have a high BMI despite having low body fat. Always consult with a doctor for a comprehensive health assessment including waist circumference and blood pressure checks.