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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. It is widely used as a screening tool to identify possible weight problems in adults. While BMI does not measure body fat directly, research has shown that BMI correlates to direct measures of body fat.
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, older adults, or those with different body compositions. It should be used as a screening tool, not a diagnostic of body fatness.
Q3: How often should I calculate my BMI?
A: For most adults, checking BMI once every few months is sufficient unless you're actively trying to change your weight.
Q4: Can BMI be used for children?
A: BMI is calculated the same way for children as adults, but the interpretation is different. For children, BMI is age and sex-specific and is referred to as BMI-for-age.
Q5: What are the limitations of BMI?
A: BMI doesn't account for muscle mass, bone density, overall body composition, and racial and sex differences. It may overestimate body fat in athletes and underestimate it in older persons.