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, normal weight, overweight and obesity in adults. It is defined as a person's weight in kilograms divided by the square of their height in meters (kg/m²).
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).
Q1: What are the standard BMI categories?
A: Underweight (BMI < 18.5), Normal weight (18.5-24.9), Overweight (25-29.9), and Obese (≥30).
Q2: Is BMI accurate for everyone?
A: BMI may overestimate body fat in athletes and those 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 or the elderly.
Q5: What's a healthy BMI range?
A: For most adults, 18.5 to 24.9 is considered healthy, though optimal range may vary by individual factors.