1. What is Body Mass Index (BMI)?

BMI is a simple index of weight-for-height that is commonly used to classify underweight, normal weight, overweight and obesity in adults. It provides a useful population-level measure of overweight and obesity.

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 is calculated by dividing weight in kilograms by the square of height in meters.

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 optionally age in years. All values must be valid (weight > 0, height > 0).

5. Frequently Asked Questions (FAQ)

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

Q2: Does BMI apply to everyone?
A: BMI may not be accurate for athletes (high muscle mass), pregnant women, or the elderly.

Q3: Why include age in the calculator?
A: While age doesn't affect BMI calculation, it provides context since BMI interpretation may vary slightly by age.

Q4: What's a healthy BMI range?
A: For most adults, 18.5 to 24.9 is considered healthy, though this may vary by ethnicity and other factors.

Q5: Should children use this calculator?
A: No, children and teens need age- and sex-specific percentiles rather than adult BMI categories.