This calculator utilizes the Devine Formula, which is the most widely recognized standard in the medical community for determining Ideal Body Weight (IBW). While "ideal weight" can be subjective, clinicians use these formulas to calculate medication dosages and determine healthy physiological benchmarks.
The Devine Formula logic is as follows:
Men: 50.0 kg + 2.3 kg for every inch over 5 feet.
Women: 45.5 kg + 2.3 kg for every inch over 5 feet.
BMI vs. Ideal Body Weight
While the Devine formula provides a specific target, health experts often suggest a "Healthy Weight Range" based on the Body Mass Index (BMI). A healthy BMI is typically defined as being between 18.5 and 24.9. Our calculator provides both the specific Devine result and the broader healthy range to give you a more complete picture of your health profile.
Example Ideal Weight Benchmarks
Height
Ideal Weight (Male)
Ideal Weight (Female)
5'4″ (162 cm)
130.5 lbs (59.2 kg)
120.6 lbs (54.7 kg)
5'8″ (173 cm)
148.8 lbs (67.5 kg)
138.9 lbs (63.0 kg)
6'0″ (183 cm)
167.1 lbs (75.8 kg)
157.2 lbs (71.3 kg)
Factors That Affect Your Result
It is important to remember that these formulas have limitations. They do not account for:
Muscle Mass: Muscle is denser than fat. Athletes often weigh more than their "ideal" weight but have very low body fat percentages.
Bone Density: Individuals with "large frames" naturally weigh more than those with "small frames."
Age: As we age, muscle mass naturally decreases and fat distribution changes.
Distribution: Where you carry your weight (e.g., visceral vs. subcutaneous fat) is often more important for health than the number on the scale.
Always consult with a healthcare professional or a registered dietitian before making significant changes to your diet or exercise routine based on these calculations.
function calculateIBW() {
var gender = document.getElementById('ibw-gender').value;
var ft = parseInt(document.getElementById('ibw-ft').value);
var inches = parseInt(document.getElementById('ibw-in').value);
var resultDiv = document.getElementById('ibw-result');
var valueDiv = document.getElementById('ibw-value');
var rangeDiv = document.getElementById('ibw-range');
var mainResText = document.getElementById('ibw-main-result');
if (isNaN(ft) || ft < 1) {
alert("Please enter a valid height in feet.");
return;
}
if (isNaN(inches)) {
inches = 0;
}
var totalInches = (ft * 12) + inches;
var inchesOverFiveFeet = totalInches – 60;
// Devine Formula
var ibwKg = 0;
if (gender === 'male') {
ibwKg = 50 + (2.3 * inchesOverFiveFeet);
} else {
ibwKg = 45.5 + (2.3 * inchesOverFiveFeet);
}
// Adjust if person is under 5 feet
if (inchesOverFiveFeet < 0) {
// Linear reduction for those under 5 feet
if (gender === 'male') {
ibwKg = 50 + (2.3 * inchesOverFiveFeet);
} else {
ibwKg = 45.5 + (2.3 * inchesOverFiveFeet);
}
}
var ibwLbs = ibwKg * 2.20462;
// BMI Healthy Range Calculation (18.5 – 24.9)
// Formula: Weight (kg) = BMI * Height(m)^2
var heightMeters = totalInches * 0.0254;
var minKg = 18.5 * (heightMeters * heightMeters);
var maxKg = 24.9 * (heightMeters * heightMeters);
var minLbs = minKg * 2.20462;
var maxLbs = maxKg * 2.20462;
mainResText.innerHTML = "Your Estimated Ideal Body Weight is:";
valueDiv.innerHTML = ibwLbs.toFixed(1) + " lbs (" + ibwKg.toFixed(1) + " kg)";
rangeDiv.innerHTML = "Healthy BMI Weight Range: " + minLbs.toFixed(1) + " – " + maxLbs.toFixed(1) + " lbs";
resultDiv.style.display = 'block';
resultDiv.scrollIntoView({ behavior: 'smooth', block: 'nearest' });
}