1. What is BMI?

Body Mass Index (BMI) is a simple calculation using a person's height and weight. The formula is BMI = kg/m² where kg is a person's weight in kilograms and m² is their height in meters squared. It provides a reliable indicator of body fatness for most people.

2. How Does the Calculator Work?

The calculator uses the standard BMI formula:

Where:

• \( weight \) — Body weight in kilograms (kg)
• \( height \) — Height in meters (m)

Explanation: The formula divides the weight by the square of the height to account for the relationship between weight and body surface area.

3. Importance of BMI Calculation

Details: BMI is used to screen for weight categories that may lead to health problems. It's a simple, inexpensive method to assess whether a person is underweight, normal weight, overweight, or obese.

4. Using the Calculator

Tips: Enter weight in kilograms and height in meters. All values must be valid (weight > 0, height > 0). For height in centimeters, divide by 100 to convert to meters.

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), Obesity (≥30).

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

Q3: Should BMI be used alone for health assessment?
A: No, it should be used along with other measurements like waist circumference and body composition analysis.

Q4: How often should BMI be calculated?
A: For adults, annual calculation is sufficient unless significant weight changes occur.

Q5: Can BMI be used for children?
A: Children's BMI is calculated the same way but interpreted differently using age- and sex-specific percentiles.