1. What is BMI?

BMI (Body Mass Index) is a simple index of weight-for-height that is commonly used to classify underweight, normal weight, overweight and obesity in adults. It is defined as a person's weight in kilograms divided by the square of their height in meters (kg/m²).

2. How Does the Calculator Work?

The calculator uses the standard BMI formula:

Where:

• \( weight_{kg} \) — Weight in kilograms
• \( height_{cm} \) — Height in centimeters
• \( height_{m} \) — Height in meters

Explanation: The formula calculates body mass per unit of height squared, providing a standardized measure of body composition.

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. It is used to screen for weight categories that may lead to health problems.

4. Using the Calculator

Tips: Enter weight in kilograms and height in centimeters. All values must be valid (weight > 0, height > 0). For most accurate results, measure weight in the morning before eating and after using the bathroom.

5. Frequently Asked Questions (FAQ)

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

Q2: 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.

Q3: What is a healthy BMI range?
A: For most adults, a healthy range is 18.5 to 24.9. However, optimal BMI may vary by age, sex, and ethnicity.

Q4: Should children use this calculator?
A: No, children and teens need age- and sex-specific BMI percentiles rather than the adult categories.

Q5: What are the limitations of BMI?
A: BMI doesn't distinguish between fat and muscle, doesn't account for fat distribution, and may not be equally applicable to all ethnic groups.