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. BMI provides a reliable indicator of body fatness for most people.

2. How Does the Calculator Work?

The calculator uses the standard BMI formula:

Where:

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

Explanation: BMI is calculated by dividing weight in kilograms by height in meters squared. The result is then compared to standard categories.

3. Importance of BMI Calculation

Details: BMI is a simple, inexpensive screening tool for weight categories that may lead to health problems. It's used to screen for weight categories that may lead to health problems but it is not diagnostic of body fatness or health.

4. Using the Calculator

Tips: Enter weight in kilograms, height in meters, and age in years. All values must be valid (weight > 0, height > 0, age ≥18).

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), 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: Why include age in the calculator?
A: While age doesn't affect BMI calculation, it provides context since healthy BMI ranges may vary slightly with age.

Q4: What's a healthy BMI for adults?
A: Generally 18.5 to 24.9, but optimal range may vary based on individual factors like muscle mass and ethnicity.

Q5: Should children use this calculator?
A: No, children and teens need age- and sex-specific percentiles rather than adult BMI categories.