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. BMI 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 a person's weight by the square of their height to categorize their weight status.

3. Importance of BMI Calculation

Details: BMI is a simple, inexpensive screening method for weight category—underweight, healthy weight, overweight, and obesity. It correlates with direct measures of body fat and is used to screen for health risks.

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). 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), Obese (≥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: Why use metric units?
A: The standard BMI formula uses kg and meters. For pounds/inches: BMI = (weight in pounds × 703) / (height in inches)².

Q4: What is a healthy BMI range?
A: For most adults, 18.5 to 24.9 is considered healthy. However, optimal BMI may vary by age, sex, and ethnicity.

Q5: Should BMI be the only measure of health?
A: No. Waist circumference, diet, physical activity, and other factors should also be considered for a complete health assessment.