BMI Explained: What Your Number Means (and Indian Ranges)

Body Mass Index (BMI) is the most common quick screen for whether your weight is in a healthy range for your height. It is easy to calculate and useful as a starting point, but it is worth understanding both what it tells you and what it doesn’t.

How BMI is calculated

BMI is your weight in kilograms divided by the square of your height in metres (kg/m²). So a person who is 1.7 m tall and weighs 70 kg has a BMI of 70 ÷ (1.7 × 1.7) = 24.2. You don’t need to do this by hand — but knowing the formula makes the number less mysterious.

Standard categories

• Under 18.5 — underweight
• 18.5 to 24.9 — normal weight
• 25 to 29.9 — overweight
• 30 and above — obese

Why Indian ranges are different

Research shows that people of South Asian origin tend to carry more body fat and face higher health risks at a lower BMI than the standard cut-offs suggest. For this reason, many Indian guidelines treat a BMI of 23 and above as overweight and 25 and above as obese. Our calculator can show these Asian/Indian ranges alongside the standard ones.

The limits of BMI

BMI only uses height and weight, so it can’t tell muscle from fat or show where fat is stored. A muscular athlete may have a “high” BMI while being very healthy, and two people with the same BMI can have very different body compositions. Treat BMI as a first indicator, not a diagnosis, and consider waist measurement and a doctor’s advice for the full picture.

To find your number and see both the standard and Indian categories, use our BMI Calculator with metric or imperial units.