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 BMI is Calculated

The calculator uses the standard BMI formula:

Where:

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

Example: For a person weighing 70 kg and 1.75 m tall: BMI = 70 / (1.75 × 1.75) = 22.9 kg/m²

3. BMI Categories

Standard BMI Categories:

• Underweight: BMI < 18.5
• Normal weight: BMI 18.5-24.9
• Overweight: BMI 25-29.9
• Obese: BMI ≥ 30

Note: BMI is a screening tool but not a diagnostic of body fatness or health. Athletes may have high BMI due to muscle mass.

4. Using the Calculator

Instructions: Enter your 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: Is BMI accurate for everyone?
A: BMI may overestimate body fat in athletes and underestimate it in older adults with lost muscle mass.

Q2: What's a healthy BMI range?
A: For most adults, 18.5 to 24.9 is considered healthy. However, optimal BMI may vary by age and ethnicity.

Q3: How much weight should I lose to improve my BMI?
A: Even 5-10% weight loss can significantly improve health if overweight. Consult a healthcare provider.

Q4: Does BMI apply to children?
A: Children's BMI is calculated differently, using percentiles based on age and sex.

Q5: What's better than BMI for health assessment?
A: Waist circumference, body fat percentage, and other measurements combined give better health picture.