What it calculates
Body Mass Index (BMI) compares weight with height. It is a quick screening measure used worldwide to group adults into weight categories.
Research suggests health risks rise at lower BMI levels for many South Asian adults, so the calculator shows both the WHO international categories and the lower cut-offs often used in India.
How it works
BMI is your weight in kilograms divided by the square of your height in metres. The result is then placed in a category.
Formula
- WHO: under 18.5 underweight; 18.5–24.9 normal; 25–29.9 overweight; 30+ obesity
- Asian Indian cut-offs: 18.5–22.9 normal; 23–24.9 overweight; 25+ obesity
How to use it
- Enter your age (adults 18+).
- Enter height in centimetres and weight in kilograms.
- Read your BMI and both category systems.
For the defaults — 165 cm and 65 kg —
Why it helps
- Fast, free screening measure.
- Shows the India-relevant cut-offs alongside the WHO ones.
- Gives the weight range that corresponds to a healthy BMI for your height.
Limitations
- Does not distinguish muscle from fat, so athletes may read high.
- Not valid for children, and less informative in pregnancy and older age.
- Waist size and other measures add useful information.
Frequently asked questions
Which categories should I use?
Many Indian health guidelines use the lower Asian cut-offs. Your doctor can tell you which applies to you.
Can I use BMI for my child?
No. Children and teenagers need age- and sex-specific growth charts.
Do you store what I enter?
No. This calculator runs entirely in your browser. Your measurements and dates are not sent to or stored on our servers.
Sources
- Obesity and overweight — fact sheet (BMI classification) — World Health Organization (checked 2026-09-27)