1. What is BMI?

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

2. How BMI is Calculated

The BMI formula is:

Where:

• Weight is measured in kilograms (kg)
• Height is measured in meters (m)

Explanation: BMI correlates fairly well with body fat in most people, though it doesn't directly measure body fat.

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

For Older Adults: Some studies suggest a slightly higher BMI range (23-27) may be optimal for older adults due to age-related body composition changes.

4. Using the Calculator

Tips: Enter weight in kilograms and height in meters. For height in centimeters, divide by 100 (e.g., 175 cm = 1.75 m).

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 the ideal BMI for seniors?
A: For adults over 65, a BMI of 23-27 may be healthier than the standard 18.5-24.9 range.

Q3: Should BMI be interpreted differently by age?
A: Yes, older adults may benefit from slightly higher BMI due to age-related changes in body composition.

Q4: What are BMI limitations?
A: BMI doesn't distinguish between muscle and fat, and doesn't account for fat distribution.

Q5: Are there better measures than BMI?
A: Waist circumference and body fat percentage may provide additional useful information.