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. It is defined as the weight in kilograms divided by the square of the height in meters (kg/m²).

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 simple, inexpensive, and non-invasive surrogate measure of body fat. While it doesn't directly measure body fat, it correlates with direct measures of body fat and offers a reasonable indicator of body fatness for most people.

4. Using the Calculator

Tips: Enter weight in kilograms and height in meters. For height, you can convert from cm to m by dividing by 100 (e.g., 175 cm = 1.75 m). All values must be valid (weight > 0, height > 0).

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 others with muscular builds and underestimate it in older persons who have lost muscle mass.

Q3: Should BMI be interpreted the same way for children?
A: No, BMI for children and teens is age- and sex-specific and is often referred to as BMI-for-age.

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

Q5: What's a healthy BMI range?
A: For most adults, a BMI between 18.5 and 24.9 is considered healthy, though individual circumstances may vary.