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, BMI must be interpreted relative to age and sex using percentile growth charts.

2. How Does the Calculator Work?

The calculator uses the standard BMI formula:

Where:

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

Explanation: 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.

3. Importance of BMI Calculation

Details: BMI is a screening tool to identify possible weight problems, though it doesn't directly measure body fat. Healthcare providers use BMI along with other assessments to evaluate health risks.

4. Using the Calculator

Tips: Enter weight in kilograms, height in meters, and age in years. For children, the result should be plotted on appropriate growth charts.

5. Frequently Asked Questions (FAQ)

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

Q2: How is BMI interpreted differently for children?
A: Children's BMI is compared to growth charts for their age and sex, expressed as percentiles rather than fixed categories.

Q3: What are limitations of BMI?
A: BMI doesn't distinguish between muscle and fat mass, and may misclassify muscular individuals as overweight or athletes as obese.

Q4: Is BMI accurate for elderly people?
A: BMI may be less accurate in elderly due to height loss and body composition changes. Waist circumference may be more informative.

Q5: How often should BMI be checked?
A: For adults, annual checks are reasonable. Children should have BMI calculated at all well-child visits after age 2.