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 screens for weight categories that may lead to health problems.

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: BMI provides a simple numeric measure of a person's thickness or thinness, allowing health professionals to discuss weight problems more objectively with their patients.

3. Importance of BMI Calculation

Details: BMI is a reliable indicator of body fatness for most people. It is used to screen for weight categories that may lead to health problems but it is not diagnostic of the body fatness or health of an individual.

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 BMI categories?
A: Underweight (BMI < 18.5), Normal weight (18.5-24.9), Overweight (25-29.9), and Obese (≥30).

Q2: Is BMI accurate for everyone?
A: BMI may overestimate body fat in athletes and others with muscular builds. It may underestimate body fat in older persons and others who have lost muscle.

Q3: Why use metric units?
A: The standard BMI formula uses kg and m. For imperial units (pounds and inches), the formula is different: BMI = (weight in pounds / (height in inches × height in inches)) × 703.

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

Q5: Should children use this calculator?
A: No, children and teens need age- and sex-specific percentiles because their body composition varies as they grow.