1. What is BMI?

Body Mass Index (BMI) is a value derived from an individual's weight and height. It provides a simple numeric measure of a person's thickness or thinness, allowing health professionals to discuss weight problems objectively with their patients.

2. How Does the Calculator Work?

The calculator uses the following formula:

Where:

• \( weight \) — Weight in pounds (lbs)
• \( height \) — Height in centimeters (cm)
• \( 0.393701 \) — Conversion factor from cm to inches
• \( 703 \) — Conversion factor for imperial units

Explanation: The formula converts height from centimeters to inches, then calculates BMI using standard imperial formula.

3. BMI Categories

Standard BMI categories:

• Underweight: BMI less than 18.5
• Normal weight: BMI 18.5 to 24.9
• Overweight: BMI 25 to 29.9
• Obese: BMI 30 or greater

4. Using the Calculator

Tips: Enter weight in pounds and height in centimeters. All values must be valid (weight > 0, height > 0).

5. Frequently Asked Questions (FAQ)

Q1: Is BMI accurate for everyone?
A: BMI may not accurately reflect body fat in athletes (who may have high muscle mass) or elderly (who may have lost muscle mass).

Q2: Why convert cm to inches in the formula?
A: The standard BMI formula for imperial units uses inches, so we convert cm to inches for accurate calculation.

Q3: What's a healthy BMI range?
A: For most adults, a healthy BMI is between 18.5 and 24.9.

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, or body fat percentage measurements may provide additional information.