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 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 that can indicate whether a person is underweight, normal weight, overweight, or obese. However, it doesn't directly measure body fat and doesn't account for muscle mass, bone density, overall body composition, and racial and sex differences.

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

Q3: Why is BMI used in eating disorder assessments?
A: BMI provides an objective measure to track weight changes, though it's just one of many factors considered in eating disorder diagnosis and treatment.

Q4: Are there different BMI standards for different populations?
A: Some countries have adjusted BMI categories for Asian populations where health risks increase at lower BMI levels.

Q5: Should children use the same BMI categories?
A: No, children and teens need age- and sex-specific BMI percentiles due to their growing bodies.