1. What is BMI?

BMI (Body Mass Index) 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.

2. How Does the BMI Calculator Work?

The calculator uses the standard BMI equation:

Where:

• \( weight \) — Body weight in kilograms (kg)
• \( height \) — Height in meters (m)

Explanation: BMI provides a simple numeric measure of a person's thickness or thinness, allowing health professionals to discuss weight problems objectively with their patients.

3. Importance of BMI Calculation

Details: BMI is an inexpensive and easy screening method for weight category - underweight, healthy weight, overweight, and obesity. It is strongly correlated with various metabolic and disease outcomes.

4. Using the Calculator

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).

5. Frequently Asked Questions (FAQ)

Q1: What are the standard BMI categories?
A: Underweight (BMI < 18.5), Normal weight (18.5-24.9), Overweight (25-29.9), Obesity (BMI ≥ 30).

Q2: Is BMI accurate for everyone?
A: BMI may overestimate body fat in athletes and those with muscular builds, and underestimate it in older persons who have lost muscle mass.

Q3: 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.

Q4: What are the limitations of BMI?
A: BMI doesn't distinguish between fat and muscle, doesn't account for fat distribution, and may not be equally valid across all ethnic groups.

Q5: What's a healthy BMI range?
A: For most adults, 18.5 to 24.9 is considered healthy. However, optimal BMI may vary by age, sex, and ethnicity.