Body Weight Calculator

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Advanced Body Weight & BMI Calculator

Male Female
Body Mass Index (BMI) —

Ideal Weight (Devine) —

kg

Health Summary

function calculateBodyMetrics() { var gender = document.getElementById('gender').value; var age = parseFloat(document.getElementById('age').value); var height = parseFloat(document.getElementById('heightCm').value); var weight = parseFloat(document.getElementById('weightKg').value); if (!age || !height || !weight || age <= 0 || height <= 0 || weight <= 0) { alert("Please enter valid positive numbers for all fields."); return; } // 1. Calculate BMI var heightInMeters = height / 100; var bmi = weight / (heightInMeters * heightInMeters); var bmiFixed = bmi.toFixed(1); // 2. BMI Category var category = ""; var categoryColor = ""; if (bmi = 18.5 && bmi = 25 && bmi < 29.9) { category = "Overweight"; categoryColor = "#f39c12"; } else { category = "Obesity"; categoryColor = "#c0392b"; } // 3. Ideal Body Weight (Devine Formula) // 5 feet = 152.4 cm. Every inch above 5ft adds weight. var heightInInches = height / 2.54; var inchesOverFiveFeet = heightInInches – 60; if (inchesOverFiveFeet < 0) inchesOverFiveFeet = 0; var ibw = 0; if (gender === "male") { ibw = 50 + (2.3 * inchesOverFiveFeet); } else { ibw = 45.5 + (2.3 * inchesOverFiveFeet); } // 4. Update UI document.getElementById('results-area').style.display = "block"; document.getElementById('bmiResult').innerHTML = bmiFixed; document.getElementById('bmiCategory').innerHTML = category; document.getElementById('bmiCategory').style.color = categoryColor; document.getElementById('ibwResult').innerHTML = ibw.toFixed(1); var summaryText = "Based on your height of " + height + " cm and weight of " + weight + " kg, your BMI is " + bmiFixed + ". "; summaryText += "For your height, the Devine formula suggests an ideal weight of approximately " + ibw.toFixed(1) + " kg. "; summaryText += "Maintaining a weight in the " + category.toLowerCase() + " range typically reduces health risks."; document.getElementById('healthSummary').innerHTML = summaryText; }

Understanding Body Weight Metrics

Managing your body weight is a fundamental aspect of long-term health and disease prevention. However, "weight" is more than just a single number on a scale. To get a clear picture of your physical status, medical professionals use various metrics, primarily the Body Mass Index (BMI) and Ideal Body Weight (IBW).

What is Body Mass Index (BMI)?

BMI is a standardized screening tool used to categorize individuals based on their height and weight. It is calculated by dividing weight in kilograms by the square of height in meters. While BMI does not measure body fat directly, it correlates moderately well with more direct measures of body fat.

Standard BMI Categories:

  • Underweight: BMI less than 18.5
  • Healthy weight: BMI 18.5 to 24.9
  • Overweight: BMI 25 to 29.9
  • Obesity: BMI 30 or greater

How is Ideal Body Weight (IBW) Calculated?

The Ideal Body Weight calculation used in our tool is based on the Devine Formula, which has been the clinical standard since 1974. Unlike BMI, which gives you a range, IBW provides a target weight based on your biological sex and height.

The formula begins with a base weight for a person who is 5 feet (152.4 cm) tall:

  • For Men: 50 kg + 2.3 kg for every inch over 5 feet.
  • For Women: 45.5 kg + 2.3 kg for every inch over 5 feet.

Example Calculations

Example 1: Average Male

Height: 180 cm (approx. 5'11")
Weight: 85 kg
BMI: 26.2 (Overweight)
Ideal Weight: 75.1 kg

Example 2: Average Female

Height: 165 cm (approx. 5'5″)
Weight: 60 kg
BMI: 22.0 (Healthy)
Ideal Weight: 56.9 kg

Why These Numbers Matter

Staying within a healthy weight range significantly reduces the risk of chronic conditions, including:

  • Type 2 Diabetes
  • Hypertension (High Blood Pressure)
  • Cardiovascular Disease
  • Sleep Apnea
  • Joint Strain and Osteoarthritis

Disclaimer: This calculator provides general estimates. It does not account for muscle mass (common in athletes), bone density, or overall body composition. Always consult with a healthcare professional or registered dietitian before making significant changes to your diet or exercise routine.

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