BMI Equation:
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BMI (Body Mass Index) is a simple index of weight-for-height that is commonly used to classify underweight, normal weight, overweight and obesity in adults. It is calculated by dividing weight in kilograms by the square of height in meters.
The calculator uses the standard BMI formula:
Where:
Explanation: The formula provides a simple numeric measure of a person's thickness or thinness, allowing health professionals to discuss weight problems objectively with their patients.
Details: BMI provides the most useful population-level measure of overweight and obesity as it is the same for both sexes and for all ages of adults. However, it should be considered a rough guide because it may not correspond to the same degree of fatness in different individuals.
Tips: Enter weight in kilograms and height in meters. For height, you can convert from cm to m by dividing by 100 (e.g., 175 cm = 1.75 m). All values must be valid (weight > 0, height > 0).
Q1: What are the standard BMI categories?
A: Underweight (<18.5), Normal weight (18.5-24.9), Overweight (25-29.9), Obesity (≥30).
Q2: Is BMI accurate for everyone?
A: BMI may overestimate body fat in athletes and others with muscular builds, and underestimate it in older persons who have lost muscle mass.
Q3: Should BMI be interpreted the same way for children?
A: No, BMI for children and teens is age- and sex-specific and is often referred to as BMI-for-age.
Q4: What are the limitations of BMI?
A: BMI doesn't distinguish between fat and muscle mass, doesn't consider fat distribution, and may not be accurate for certain ethnic groups.
Q5: What's a healthy BMI range?
A: For most adults, 18.5 to 24.9 is considered healthy, though optimal BMI may vary by ethnicity and other factors.