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 the weight in kilograms divided by the square of the height in meters (kg/m²).

2. How Does the Calculator Work?

The calculator uses the standard BMI formula:

Where:

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

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

3. Importance of BMI Calculation

Details: BMI is an inexpensive and easy screening method for weight category—underweight, healthy weight, overweight, and obesity. While BMI doesn't measure body fat directly, research has shown that BMI correlates to direct measures of body fat.

4. Using the Calculator

Tips: Enter weight in kilograms and height in meters. For pounds and inches, first convert to metric units (1 kg = 2.2 lbs, 1 m = 39.37 inches).

5. Frequently Asked Questions (FAQ)

Q1: What are the standard 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 others with muscular builds, and underestimate body fat in older persons and others who have lost muscle.

Q3: What is a healthy BMI range?
A: For most adults, an ideal BMI is in the 18.5 to 24.9 range.

Q4: Should children use the same BMI categories?
A: No, children and teens need age- and sex-specific percentiles because their body composition varies as they grow.

Q5: What are alternatives to BMI?
A: Waist circumference, waist-to-hip ratio, and body fat percentage measurements can provide additional information.