Healthy Weight Calculator
Use this calculator to estimate your Body Mass Index (BMI) and determine if your weight falls within a healthy range for your height. BMI is a widely used screening tool, but it's important to remember its limitations and consult a healthcare professional for personalized advice.
Understanding Your BMI
Body Mass Index (BMI) is a measure that uses your height and weight to work out if your weight is healthy. It's calculated by dividing your weight in kilograms by the square of your height in meters (kg/m²).
BMI Categories:
- Underweight: Less than 18.5
- Normal weight: 18.5 – 24.9
- Overweight: 25 – 29.9
- Obese: 30 or greater
Limitations of BMI:
While BMI is a useful screening tool, it has limitations:
- It doesn't distinguish between fat and muscle mass. Athletes with high muscle mass might have a high BMI but low body fat.
- It doesn't account for body fat distribution. Waist circumference can be a better indicator of health risks.
- It may not be accurate for certain populations, such as the elderly, children, or pregnant women.
- Different ethnic groups may have different healthy BMI ranges.
Always consult with a healthcare professional for a comprehensive assessment of your health and weight status. They can consider other factors like body composition, diet, lifestyle, and medical history to provide personalized recommendations.
Examples:
Let's look at a few examples:
- Example 1: A person weighing 70 kg and standing 1.75 m (175 cm) tall.
BMI = 70 / (1.75 * 1.75) = 70 / 3.0625 = 22.86. This falls into the "Normal weight" category.
Ideal weight range for this height (18.5 to 24.9 BMI): 56.5 kg to 76.2 kg.
- Example 2: A person weighing 180 lbs and standing 5 feet 10 inches (70 inches) tall.
Weight in kg = 180 * 0.453592 = 81.65 kg.
Height in cm = 70 * 2.54 = 177.8 cm.
Height in meters = 1.778 m.
BMI = 81.65 / (1.778 * 1.778) = 81.65 / 3.161284 = 25.82. This falls into the "Overweight" category.
Ideal weight range for this height (18.5 to 24.9 BMI): 58.4 kg to 78.8 kg (or 128.7 lbs to 173.7 lbs).
.healthy-weight-calculator-container {
font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
max-width: 700px;
margin: 20px auto;
padding: 25px;
background-color: #f9f9f9;
border-radius: 10px;
box-shadow: 0 4px 12px rgba(0, 0, 0, 0.1);
color: #333;
}
.healthy-weight-calculator-container h2,
.healthy-weight-calculator-container h3,
.healthy-weight-calculator-container h4 {
color: #2c3e50;
text-align: center;
margin-bottom: 20px;
}
.healthy-weight-calculator-container p {
line-height: 1.6;
margin-bottom: 15px;
}
.calculator-form .form-group {
display: flex;
align-items: center;
margin-bottom: 15px;
gap: 10px;
}
.calculator-form label {
flex: 1;
font-weight: bold;
color: #555;
}
.calculator-form input[type="number"],
.calculator-form select {
flex: 2;
padding: 10px;
border: 1px solid #ccc;
border-radius: 5px;
font-size: 16px;
box-sizing: border-box;
}
.calculator-form input[type="number"] {
flex: 1.5; /* Adjust width for number input */
}
.calculator-form select {
flex: 0.5; /* Adjust width for select */
min-width: 80px;
}
.calculate-button {
display: block;
width: 100%;
padding: 12px 20px;
background-color: #28a745;
color: white;
border: none;
border-radius: 5px;
font-size: 18px;
cursor: pointer;
transition: background-color 0.3s ease;
margin-top: 20px;
}
.calculate-button:hover {
background-color: #218838;
}
.calculator-result {
margin-top: 25px;
padding: 15px;
background-color: #e9f7ef;
border: 1px solid #d4edda;
border-radius: 8px;
font-size: 17px;
color: #155724;
text-align: center;
font-weight: bold;
}
.calculator-result p {
margin: 5px 0;
}
.calculator-result .bmi-value {
font-size: 24px;
color: #007bff;
}
.calculator-result .bmi-category {
font-size: 20px;
margin-top: 10px;
}
.healthy-weight-calculator-container ul {
list-style-type: disc;
margin-left: 20px;
margin-bottom: 15px;
}
.healthy-weight-calculator-container ul li {
margin-bottom: 8px;
line-height: 1.5;
}
@media (max-width: 600px) {
.calculator-form .form-group {
flex-direction: column;
align-items: flex-start;
}
.calculator-form label {
width: 100%;
margin-bottom: 5px;
}
.calculator-form input[type="number"],
.calculator-form select {
width: 100%;
flex: none;
}
}
function calculateHealthyWeight() {
var weightInput = document.getElementById("weightInput").value;
var weightUnit = document.getElementById("weightUnit").value;
var heightInput = document.getElementById("heightInput").value;
var heightUnit = document.getElementById("heightUnit").value;
var gender = document.getElementById("genderSelect").value; // For context
var age = document.getElementById("ageInput").value; // For context
var resultDiv = document.getElementById("result");
resultDiv.innerHTML = ""; // Clear previous results
// Input validation
if (isNaN(weightInput) || weightInput <= 0 || isNaN(heightInput) || heightInput <= 0) {
resultDiv.style.backgroundColor = '#f8d7da';
resultDiv.style.borderColor = '#f5c6cb';
resultDiv.style.color = '#721c24';
resultDiv.innerHTML = "Please enter valid positive numbers for weight and height.";
return;
}
var weightKg;
if (weightUnit === "lbs") {
weightKg = parseFloat(weightInput) * 0.453592;
} else {
weightKg = parseFloat(weightInput);
}
var heightMeters;
if (heightUnit === "inches") {
heightMeters = parseFloat(heightInput) * 0.0254; // inches to meters
} else {
heightMeters = parseFloat(heightInput) / 100; // cm to meters
}
var bmi = weightKg / (heightMeters * heightMeters);
var bmiCategory = "";
var categoryColor = "";
if (bmi = 18.5 && bmi = 25 && bmi <= 29.9) {
bmiCategory = "Overweight";
categoryColor = "#fd7e14"; // Orange
} else {
bmiCategory = "Obese";
categoryColor = "#dc3545"; // Red
}
// Calculate ideal weight range
var idealWeightLowerKg = 18.5 * (heightMeters * heightMeters);
var idealWeightUpperKg = 24.9 * (heightMeters * heightMeters);
var idealWeightRangeText = "";
if (weightUnit === "lbs") {
var idealWeightLowerLbs = idealWeightLowerKg / 0.453592;
var idealWeightUpperLbs = idealWeightUpperKg / 0.453592;
idealWeightRangeText = idealWeightLowerLbs.toFixed(1) + " lbs – " + idealWeightUpperLbs.toFixed(1) + " lbs";
} else {
idealWeightRangeText = idealWeightLowerKg.toFixed(1) + " kg – " + idealWeightUpperKg.toFixed(1) + " kg";
}
resultDiv.style.backgroundColor = '#e9f7ef';
resultDiv.style.borderColor = '#d4edda';
resultDiv.style.color = '#155724';
resultDiv.innerHTML =
"Your BMI:
" + bmi.toFixed(2) + "" +
"Category:
" + bmiCategory + "" +
"Ideal Weight Range for your height:
" + idealWeightRangeText + "" +
"
Remember, BMI is a screening tool. Consult a healthcare professional for personalized advice.";
}