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BMI Formula:
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Body Mass Index (BMI) is a simple index of weight-for-height that is commonly used to classify underweight, overweight and obesity in adults. It is defined as the weight in kilograms divided by the square of the height in meters (kg/m²).
The calculator uses the standard BMI formula:
Where:
Explanation: The calculator also takes into account build type (muscular, average, slender) to provide context for interpreting the BMI result.
Details: BMI provides a simple numeric measure of a person's thickness or thinness, allowing health professionals to discuss weight problems more objectively with their patients.
Tips: Enter weight in kilograms, height in meters, and select your build type. All values must be valid (weight > 0, height > 0).
Q1: Why consider build type in BMI calculation?
A: BMI doesn't distinguish between muscle and fat. Muscular individuals may have high BMI without excess fat, while slender individuals may have normal BMI but high body fat percentage.
Q2: What are standard BMI categories?
A: Underweight (<18.5), Normal (18.5-24.9), Overweight (25-29.9), Obese (≥30). These may vary slightly by ethnicity.
Q3: Are there better alternatives to BMI?
A: For individuals, body fat percentage measurements (via skinfold calipers, DEXA scans, etc.) may be more accurate, but BMI remains useful for population-level assessments.
Q4: Does BMI apply to everyone?
A: BMI may not be accurate for children, pregnant women, the elderly, or those with unusual body compositions (e.g., athletes, amputees).
Q5: How often should I check my BMI?
A: For most adults, checking every 3-6 months is sufficient unless you're actively trying to change your weight or body composition.