BMI Formula:
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BMI (Body Mass Index) is a simple calculation using a person's height and weight. The formula is BMI = kg/m² where kg is a person's weight in kilograms and m² is their height in meters squared. It provides a numeric measure of a person's thickness or thinness.
The calculator uses the BMI formula:
Where:
Explanation: BMI is calculated by dividing weight in kilograms by the square of height in meters.
Details: BMI is a simple, inexpensive screening method for weight category—underweight, healthy weight, overweight, and obesity. While it doesn't measure body fat directly, research has shown BMI to be correlated with more direct measures of body fat.
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 (<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: Why is BMI used if it's not perfect?
A: It's a simple, standardized method that works well for most people to screen for potential weight problems.
Q4: Should children use the same BMI categories?
A: No, children and teens need age- and sex-specific percentiles because their body composition varies as they grow.
Q5: What's better than BMI for measuring health?
A: While BMI is useful for populations, waist circumference and other risk factors provide better individual health assessment.