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

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: The formula 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, normal weight, overweight, and obesity. It correlates with more direct measures of body fat and is strongly associated with various metabolic and disease outcomes.

4. Using the Calculator

Tips: Enter weight in kilograms and height in meters. For height, you can convert from cm to m by dividing by 100 (e.g., 175 cm = 1.75 m). All values must be valid (weight > 0, height > 0).

5. Frequently Asked Questions (FAQ)

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

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

Q3: How often should I check my BMI?
A: For most adults, checking BMI annually is sufficient unless you're actively trying to lose or gain weight.

Q4: Does BMI apply to children?
A: BMI for children and teens is interpreted relative to age and sex-specific percentiles rather than fixed categories.

Q5: What's a healthy BMI range?
A: For most adults, a BMI between 18.5 and 24.9 is considered healthy, though optimal range may vary by ethnicity.