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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, normal weight, overweight and obesity in adults. It is calculated by dividing a person's weight in kilograms by the square of their 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 more objectively with their patients.
Details: BMI is an inexpensive and easy screening method for weight category - underweight, healthy weight, overweight, and obesity. It correlates moderately well with direct measures of body fatness and is strongly correlated with various metabolic and disease outcomes.
Tips: Enter weight in kilograms and height in meters. For most accurate results, measure weight without heavy clothing and height without shoes. All values must be valid (weight > 0, height > 0).
Q1: What are the BMI categories for adults?
A: Underweight (<18.5), Normal weight (18.5-24.9), Overweight (25-29.9), Obese (≥30).
Q2: Is BMI different for women and men?
A: The same BMI ranges apply to both women and men, though women tend to have more body fat than men at the same BMI.
Q3: What are the limitations of BMI?
A: BMI doesn't distinguish between fat and muscle, so muscular individuals may have a high BMI without excess fat. It also may not accurately reflect body fat in the elderly or those who have lost muscle mass.
Q4: How often should I check my BMI?
A: For most adults, checking BMI once every 6-12 months is sufficient unless you're actively trying to lose or gain weight.
Q5: Is BMI suitable for all ethnic groups?
A: While BMI is widely used, some ethnic groups may have different health risks at the same BMI levels. For example, Asian populations may have higher health risks at lower BMI levels.