1. What is BMI?

Body Mass Index (BMI) is a simple index of weight-for-height that is commonly used to classify underweight, normal weight, overweight and obesity in adults. It is calculated by dividing a person's weight in kilograms by the square of their height in meters.

2. How Does the Calculator Work?

The calculator uses the BMI formula:

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 more objectively with their patients.

3. Importance of BMI Calculation

Details: BMI is a simple, inexpensive, and noninvasive surrogate measure of body fat. While not a direct measure of body fat, BMI is moderately correlated with more direct measures of body fat. It also correlates with various metabolic and disease outcomes.

4. Using the Calculator

Tips: Enter weight in kilograms and height in meters. All values must be valid (weight > 0, height > 0). For accurate results, measure height without shoes and weight with minimal clothing.

5. Frequently Asked Questions (FAQ)

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

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

Q3: Can BMI be used for children?
A: Children's BMI is age and sex-specific and is often referred to as BMI-for-age. This calculator is for adults only.

Q4: What are the limitations of BMI?
A: BMI doesn't distinguish between weight from fat versus muscle, doesn't consider fat distribution, and may not be accurate for certain ethnic groups or elderly.

Q5: Should BMI be the only measure of healthy weight?
A: No, waist circumference and other risk factors should also be considered for a complete health assessment.