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 a person's weight in kilograms divided by the square of their height in meters (kg/m²).

2. How Is BMI Calculated?

The BMI is calculated using the following 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

4. Using the Calculator

Instructions: Enter your weight in kilograms and height in meters. The calculator will compute your BMI and classify it according to standard categories.

5. Frequently Asked Questions (FAQ)

Q1: Is BMI accurate for everyone?
A: BMI is a useful screening tool but doesn't account for muscle mass, bone density, or fat distribution. Athletes may have high BMI due to muscle rather than fat.

Q2: What are the limitations of BMI?
A: BMI doesn't distinguish between fat and muscle, doesn't account for fat distribution, and may not be accurate for certain populations (children, elderly, pregnant women).

Q3: Should children use this calculator?
A: No, children and teens need age- and sex-specific BMI percentiles rather than adult categories.

Q4: What's a healthy BMI range?
A: For most adults, 18.5 to 24.9 is considered healthy, but individual health factors should also be considered.

Q5: How often should I check my BMI?
A: Periodic checks (every 6-12 months) can help track changes, but focus should be on overall health rather than just BMI.