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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 a person's weight in kilograms divided by the square of their height in meters (kg/m²).
The calculator uses the BMI formula:
Where:
Explanation: 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.
Details: BMI is a simple, inexpensive, and noninvasive surrogate measure of body fat. While it doesn't measure body fat directly, research has shown that BMI correlates to direct measures of body fat. It is used to screen for weight categories that may lead to health problems.
Tips: Enter weight in kilograms and height in meters. All values must be valid (weight > 0, height > 0). For accurate results, measure weight and height precisely.
Q1: What are the standard BMI categories?
A: Underweight (BMI < 18.5), Normal weight (BMI 18.5-24.9), Overweight (BMI 25-29.9), Obesity (BMI ≥ 30).
Q2: Is BMI accurate for everyone?
A: BMI may not accurately reflect body fat percentage in athletes (who may have higher muscle mass), the elderly (who may have lost muscle mass), or certain ethnic groups.
Q3: Can children use the same BMI calculator?
A: No, children and teens need age- and sex-specific percentiles because their body composition varies as they age and differs between boys and girls.
Q4: What are the limitations of BMI?
A: BMI doesn't distinguish between muscle and fat, doesn't account for fat distribution, and may not be accurate for certain populations like pregnant women or very muscular individuals.
Q5: Should BMI be the only measure of health?
A: No, BMI should be used as a screening tool but not as a diagnostic of body fatness or health. Other factors like waist circumference, diet, physical activity, and family history should be considered.