1. What is BMI?

Body Mass Index (BMI) is a simple index of weight-for-height that is commonly used to classify underweight, overweight and obesity in adults. It is defined as the weight in kilograms divided by the square of the height in meters (kg/m²).

2. How Does the Calculator Work?

The calculator uses the standard BMI formula:

Where:

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

Explanation: The formula calculates body mass per unit of height squared to estimate body fatness.

3. Importance of BMI Calculation

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

4. Using the Calculator

Tips: Enter weight in kilograms and height in meters. For pounds and inches, convert first (1 kg = 2.2 lbs, 1 m = 39.37 inches).

5. Frequently Asked Questions (FAQ)

Q1: What are the BMI categories for adults?
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: Why use metric units?
A: The standard BMI formula uses kg and m. For imperial units, the formula is [weight (lbs) × 703] / [height (in)]².

Q4: What's a healthy BMI range?
A: For most adults, 18.5 to 24.9 is considered healthy, though optimal may vary by individual.

Q5: Does BMI apply to children?
A: Children's BMI is calculated differently using percentiles specific to age and sex.