What BMI tells you
BMI is weight in kilograms divided by height in metres squared. A person who is 70kg and 170cm has a BMI of 70 ÷ (1.70 × 1.70) = 24.2. That’s it.
The number puts you in a category. For the general WHO scale: below 18.5 is underweight, 18.5–24.9 is normal, 25–29.9 is overweight, 30 and above is obese.
Why Indians need a different scale
This matters. Indians and other South Asians carry more body fat at the same BMI as Europeans. A study published in the Lancet found Indian adults develop diabetes and cardiovascular risk at BMI levels considered “normal” on the WHO scale.
The Asian BMI cutoffs used here are: below 18.5 underweight, 18.5–22.9 normal, 23–27.4 overweight, 27.5 and above obese. The calculator shows both.
Limitations of BMI
BMI doesn’t distinguish muscle from fat. A 75kg person who lifts weights regularly will have a higher BMI than a sedentary person at the same height — but far less body fat. Use the body fat calculator alongside BMI for a fuller picture.
Pregnant women, children under 18, and competitive athletes should not use BMI as a health indicator.
Ideal weight range
The calculator shows the weight range that corresponds to BMI 18.5–25 at your height. That’s the target band, not a single number.
Related: Body Fat Calculator · TDEE & Calorie Calculator · Water Intake Calculator