BMI Calculator

Body Mass Index (BMI) is calculated by dividing weight in kilograms by the square of height in meters: BMI = weight(kg) / height(m)². For imperial units, the formula adjusts: BMI = (weight(lbs) * 703) / height(inches)². The multiplication by 703 is the conversion factor that accounts for the unit difference between metric and imperial. BMI Categories (WHO standard): - Underweight: BMI < 18.5 - Normal weight: 18.5 ≤ BMI < 25.0 - Overweight: 25.0 ≤ BMI < 30.0 - Obese (Class I): 30.0 ≤ BMI < 35.0 - Obese (Class II): 35.0 ≤ BMI < 40.0 - Obese (Class III): BMI ≥ 40.0 The tool includes input validation to prevent unrealistic values (height must be between 50cm and 300cm, weight between 1kg and 500kg).

1. Select your preferred unit system: Metric (kg/cm) or Imperial (lbs/inches). 2. Enter your weight. 3. Enter your height. 4. Your BMI is calculated instantly with the category classification. 5. The color indicator shows your BMI category visually.

BMI is a screening tool, not a diagnostic measure. It has several limitations: Athletes: Muscular individuals may have a high BMI despite having low body fat, because muscle is denser than fat. Elderly: BMI may underestimate body fat in older adults who have lost muscle mass. Children: BMI-for-age percentiles should be used for children and teens, not standard adult categories. Ethnicity: BMI cutoff points may vary for different ethnic groups. Asian populations may have higher health risks at lower BMI values. Pregnancy: BMI should not be used during pregnancy. For a comprehensive health assessment, consult a healthcare professional who can consider waist circumference, body fat percentage, and other clinical factors.