BMI Calculator
Your Body Mass Index from your height and weight, with the healthy weight range that goes with it. Nothing is uploaded.
Indian guidelines treat 23 as the overweight threshold rather than 25. There is more on this below.
This is a screening number, not medical advice, and it cannot tell muscle from fat. Talk to a doctor before acting on it.
■ under ■ healthy ■ over ■ obese
How to use it
- Choose metric or imperial units.
- Enter your height and your weight.
- The BMI, the category and your healthy weight range appear as you type. There is no button to press.
What BMI actually measures
Body Mass Index is your weight divided by the square of your height. That is the whole formula. It was designed in the 1830s to describe populations, not individuals, and it became popular because it needs only two numbers that anyone can measure.
What it cannot do is look inside you. BMI has no idea whether your weight is muscle, fat, bone or water. A fit sportsperson often measures as overweight, while someone with very little muscle can sit inside the healthy band while carrying too much fat. It is a screening number, and the right response to a surprising one is a conversation with a doctor, not a diet.
The standard ranges
- Below 18.5 — underweight
- 18.5 to 24.9 — healthy weight
- 25.0 to 29.9 — overweight
- 30.0 and above — obese
Why India uses different numbers
Those ranges came from studies of European populations, and they do not transfer cleanly. Research across South Asia found that the health risks that BMI is meant to flag — type 2 diabetes, high blood pressure, heart disease — begin at a lower BMI in people of Indian and other Asian descent, partly because of where the body tends to store fat.
Indian guidelines therefore move the thresholds down: overweight starts at 23 rather than 25, and obesity at 25 rather than 30. Tick Use Asian-Indian cutoffs and this page applies them. The BMI number itself does not change — only the label attached to it, and the healthy weight range that follows.
If you are unsure which set applies to you, that is exactly the kind of question to put to a doctor rather than to a website.
Frequently asked questions
Why does this calculator have separate Asian-Indian cutoffs?
Because the standard BMI ranges were drawn from European populations, and research across South Asia found that health risks such as diabetes and heart disease begin at a lower BMI. Indian guidelines therefore treat 23 as the overweight threshold rather than 25. Tick the Asian-Indian box to use those ranges.
Is BMI accurate for everyone?
No. BMI is a rough screening number, not a diagnosis. It cannot tell muscle from fat, so a fit athlete can measure as overweight. It is also unreliable for children, pregnant women, the very elderly and the very short or tall. Treat it as one number among many.
How is BMI calculated?
BMI is your weight in kilograms divided by the square of your height in metres. For imperial units the formula is 703 times your weight in pounds, divided by the square of your height in inches. This page shows the working under the result.
Is my information sent anywhere?
No. Your height and weight are used by JavaScript inside your own browser and are never transmitted or stored. Nothing is uploaded and nothing is saved — close the tab and it is gone.