1. What is BMI?

Body Mass Index (BMI) 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. BMI provides a reliable indicator of body fatness for most people and is used to screen for weight categories that may lead to health problems.

2. How Does the Calculator Work?

The calculator uses the standard BMI formula:

Where:

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

Explanation: The result is interpreted differently based on age, with specific categories for children/adolescents and adults.

3. Importance of BMI Calculation

Details: BMI is a simple, inexpensive screening method for weight categories that may lead to health problems. For children and teens, BMI is age- and sex-specific and often referred to as BMI-for-age.

4. Using the Calculator

Tips: Enter weight in kg, height in meters, and age in years. All values must be valid (weight > 0, height > 0, age between 0-120).

5. Frequently Asked Questions (FAQ)

Q1: What's a healthy BMI range?
A: For adults 20+, 18.5-24.9 is considered healthy. For children, BMI is compared against growth charts.

Q2: Does BMI apply to athletes?
A: BMI may overestimate body fat in athletes with muscular build and underestimate it in older people who have lost muscle.

Q3: How often should BMI be checked?
A: For adults, annually is sufficient. For children, more frequent monitoring may be needed during growth spurts.

Q4: Are there better measures than BMI?
A: Waist circumference and body fat percentage provide additional information, but BMI remains the standard screening tool.

Q5: How does BMI interpretation differ for children?
A: Children's BMI is compared against growth charts for their age and sex, expressed as a percentile rather than absolute number.