BMI Formula:
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BMI (Body Mass Index) 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 weight in kilograms by the square of 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 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). All values must be valid (weight > 0, height > 0).
Q1: What are the BMI categories?
A: Underweight (<18.5), Normal weight (18.5-24.9), Overweight (25-29.9), Obese (≥30).
Q2: Is BMI accurate for everyone?
A: BMI may not be accurate for athletes (muscle weighs more than fat), pregnant women, the elderly, or people with unusual body proportions.
Q3: What's a healthy BMI range?
A: For most adults, 18.5 to 24.9 is considered healthy. However, optimal BMI may vary by ethnicity and other factors.
Q4: Should children use this calculator?
A: No, children and teens need age- and sex-specific BMI percentiles rather than the adult categories.
Q5: What are the health risks of high BMI?
A: Higher BMI is associated with increased risk of heart disease, stroke, type 2 diabetes, and certain cancers.