Bmi Calculator

BMI — Body Mass Index — is probably the most commonly used and most commonly misunderstood health metric in the world. Your doctor uses it. Fitness apps obsess over it. Insurance companies calculate premiums with it. And yet, most people do not fully understand what BMI actually tells you and what it does not.

BMI is calculated by dividing your weight in kilograms by the square of your height in meters. A person who is 70 kg and 1.75 m tall has a BMI of 22.9. That falls in the normal weight range. Simple math, useful starting point.

The BMI Categories Explained

Underweight is below 18.5 — can indicate malnutrition or underlying health conditions. Normal weight is 18.5 to 24.9 — generally associated with lowest health risks. Overweight is 25 to 29.9 — increased risk of certain health conditions. Obese is 30 and above — significantly higher risk for diabetes, heart disease and other conditions.

The Important Limitations of BMI

BMI does not distinguish between muscle and fat. A professional weightlifter may have a BMI of 29 — technically overweight — with only 10% body fat and excellent health. Meanwhile, someone with the same BMI could have 35% body fat and poor metabolic health.

BMI also does not account for age, sex or ethnicity. Many Indian health organizations suggest a lower normal range — 18.5 to 22.9 — because South Asian populations tend to carry more abdominal fat at lower BMI levels and face higher health risks at the same BMI as Western populations.

What BMI Is Actually Good For

Despite its limitations, BMI is useful as a quick screening tool. If your BMI is 35, that is a strong signal to talk to a doctor regardless of how you feel. Think of BMI as a first filter — not a final answer. Use it to know whether a deeper conversation with a healthcare professional makes sense.