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 a person's weight in kilograms divided by the square of their height in meters.

2. How Does the Calculator Work?

The calculator uses the BMI formula:

Where:

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

Explanation: The formula calculates body mass per unit of surface area, providing a standardized way to compare weights across different heights.

3. Importance of BMI Calculation

Details: BMI is a simple, inexpensive screening tool for weight categories that may lead to health problems. It helps identify potential weight problems in adults.

4. Using the Calculator

Tips: Enter weight in kilograms and height in meters. All values must be valid (weight > 0, height > 0). For pounds and inches, first convert to metric units.

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 underestimate it in older people who have lost muscle mass.

Q3: What is a healthy BMI range?
A: For most adults, 18.5 to 24.9 is considered healthy.

Q4: Should children use this calculator?
A: No, children and teens need age- and sex-specific BMI percentiles.

Q5: What are alternatives to BMI?
A: Waist circumference, waist-to-hip ratio, and body fat percentage measurements may provide additional information.