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. AARP recommends BMI as a screening tool for weight categories.

2. How Does the BMI Calculator Work?

The calculator uses the standard BMI equation:

Where:

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

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

3. Importance of BMI Calculation

Details: BMI is a useful measure of overweight and obesity. It is used to screen for weight categories that may lead to health problems but is not diagnostic of body fatness or health.

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). All values must be valid (weight > 0, height > 0).

5. Frequently Asked Questions (FAQ)

Q1: What are the BMI categories?
A: Underweight (BMI < 18.5), Normal weight (18.5-24.9), Overweight (25-29.9), and Obese (≥30).

Q2: Is BMI accurate for everyone?
A: BMI may overestimate body fat in athletes and underestimate it in older persons who have lost muscle mass.

Q3: What is a healthy BMI for older adults?
A: AARP suggests a BMI between 23-30 may be healthiest for adults over 65, as some extra weight may be protective.

Q4: Should BMI be the only measure of healthy weight?
A: No, waist circumference and other risk factors should also be considered for a complete assessment.

Q5: How often should I check my BMI?
A: For most adults, checking every 6-12 months is sufficient unless you're actively trying to change your weight.