1. What is BMI?

Body Mass Index (BMI) is a simple index of weight-for-height that is commonly used to classify underweight, overweight and obesity in adults. For children and teens, BMI is age- and sex-specific and is often referred to as BMI-for-age.

2. How Does the Calculator Work?

The calculator uses the standard BMI formula:

Where:

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

For children and teens: The calculator provides the BMI value but interpretation requires comparison to age- and sex-specific percentiles.

3. Importance of BMI Calculation

Details: 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.

4. Using the Calculator

Tips: Enter weight in kilograms, height in meters, and age in years. For children under 20, consult pediatric growth charts for proper interpretation.

5. Frequently Asked Questions (FAQ)

Q1: 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.

Q2: What are the BMI categories for adults?
A: Underweight (<18.5), Normal weight (18.5-24.9), Overweight (25-29.9), Obese (≥30).

Q3: How is BMI different for children?
A: Children's BMI is plotted on growth charts to determine percentiles which indicate how their BMI compares to peers of same age and sex.

Q4: When should BMI be measured?
A: BMI should be measured at least annually, or more frequently if weight management is a concern.

Q5: Are there better measures than BMI?
A: While BMI is useful for population studies, individual assessments may benefit from additional measures like waist circumference or body fat percentage.