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)

Python Example:

def calculate_bmi(weight_kg, height_m):
    return weight_kg / (height_m ** 2)
    
weight = 70  # kg
height = 1.75  # meters
bmi = calculate_bmi(weight, height)
print(f"BMI: {bmi:.1f} kg/m²")
                    

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 of classifying underweight, normal weight, overweight and obesity.

4. Using the Calculator

Tips: Enter weight in kilograms and height in meters. For height in centimeters, divide by 100 (e.g., 175 cm = 1.75 m).

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: What are limitations of BMI?
A: Doesn't directly measure body fat, doesn't account for muscle mass, bone density, or fat distribution.

Q4: How often should I check my BMI?
A: For most adults, checking every 6-12 months is sufficient unless actively trying to change weight.

Q5: Should children use the same BMI categories?
A: No, children and teens need age- and sex-specific percentiles rather than fixed categories.