1. What Is BMI?

BMI (Body Mass Index) is a simple index of weight-for-height that is commonly used to classify underweight, normal weight, overweight and obesity in adults.

2. How Is BMI Calculated?

The BMI is calculated using the following formula:

Where:

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

Explanation: BMI is calculated by dividing a person's weight in kilograms by the square of their height in meters.

3. BMI Categories

Classification:

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

4. Using the Calculator

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

5. Frequently Asked Questions (FAQ)

Q1: Is BMI accurate for everyone?
A: BMI may not be accurate for athletes (high muscle mass), pregnant women, or the elderly (muscle loss).

Q2: What are the limitations of BMI?
A: BMI doesn't distinguish between muscle and fat mass or account for fat distribution.

Q3: Should children use this calculator?
A: No, children 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.

Q5: How often should I check my BMI?
A: Periodic checks (every 6-12 months) can help track weight status changes.