1. What is BMI?

Body Mass Index (BMI) is a value derived from the mass and height of a person. The BMI is defined as the body mass divided by the square of the body height, and is expressed in units of kg/m².

2. How Does the Calculator Work?

The calculator uses the standard BMI equation:

Where:

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

Smart Adjustment: For individuals over 65, the calculator applies a small adjustment factor to account for age-related changes in body composition.

3. Importance of BMI Calculation

Details: 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.

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 between 18-120).

5. Frequently Asked Questions (FAQ)

Q1: What is a healthy BMI range?
A: For adults, 18.5 to 24.9 is considered normal weight, 25-29.9 overweight, and 30+ obese.

Q2: Why does age matter in BMI calculation?
A: Body composition changes with age - older adults may have higher BMI values despite similar health risks.

Q3: What are the limitations of BMI?
A: BMI doesn't distinguish between muscle and fat, and may not be accurate for athletes, pregnant women, or the elderly.

Q4: Should BMI be interpreted differently for men?
A: Men typically have more muscle mass than women, so BMI thresholds might be slightly adjusted for athletic men.

Q5: Is BMI useful for children?
A: No, this calculator is for adults only. Children's BMI needs to be interpreted using age- and sex-specific percentiles.