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 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 BMI formula:

Where:

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

Explanation: The formula converts height from centimeters to meters (by dividing by 100) and then calculates the ratio of weight to height squared.

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 and height in centimeters. 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), Obese (≥30).

Q2: Is BMI accurate for everyone?
A: BMI may not accurately reflect body fat in muscular individuals, athletes, or elderly with reduced muscle mass.

Q3: How often should I check my BMI?
A: For most adults, checking every few months is sufficient unless you're actively trying to change your weight.

Q4: Are there limitations to BMI?
A: BMI doesn't distinguish between muscle and fat, and doesn't account for fat distribution (e.g., abdominal fat).

Q5: Should children use the same BMI categories?
A: No, children's BMI is interpreted using age- and sex-specific percentiles rather than fixed categories.