BMI Calculator

BMI Calculator — Understanding Body Mass Index

Body Mass Index (BMI) is a numerical value calculated from a person's weight and height. It provides a simple, widely used measure for classifying a person's weight relative to their height. While it is not a perfect measure of health, BMI is used globally by doctors, fitness professionals, and health organizations as a screening tool.

BMI Formula

Metric: BMI = Weight (kg) ÷ Height² (m²)

Imperial: BMI = 703 × Weight (lbs) ÷ Height² (inches²)

For example, a person who weighs 70 kg and is 175 cm (1.75 m) tall has a BMI of: 70 ÷ (1.75 × 1.75) = 70 ÷ 3.0625 = 22.9 (Normal Weight).

BMI Categories (WHO Standard)

• Below 18.5 — Underweight: May indicate malnutrition, eating disorders, or other health issues.
• 18.5 to 24.9 — Normal Weight: Associated with the lowest health risks for most adults.
• 25 to 29.9 — Overweight: Increased risk of heart disease, type 2 diabetes, and high blood pressure.
• 30 and above — Obese: Significantly higher risk of serious health conditions.

Limitations of BMI

BMI is a useful screening tool but has important limitations:

• It does not differentiate between muscle and fat. Athletes with high muscle mass may have a high BMI but low body fat.
• It does not account for fat distribution — abdominal (visceral) fat is more dangerous than fat in other areas.
• BMI thresholds may not apply equally to all ethnic groups.
• It is not suitable for children, pregnant women, or the elderly without modified calculations.

Always consult a healthcare professional for a complete health assessment.