What is a BMI calculator?
BMI = weight in kg ÷ (height in metres)². A 170 cm, 68 kg adult has a BMI of 23.5. WHO calls 18.5–24.9 normal, but WHO and Indian guidelines suggest Asian adults treat 23 and above as overweight because health risks rise at lower BMI.
Features
- cm and kg, or feet, inches and pounds
- WHO adult categories
- Asian adult cut-offs
- Healthy weight range for your height
How to use the BMI calculator
- Choose your units.
- Enter height and weight.
- Read your BMI, category and healthy range.
BMI categories
| Category | WHO | Asian adults |
|---|---|---|
| Underweight | below 18.5 | below 18.5 |
| Normal | 18.5–24.9 | 18.5–22.9 |
| Overweight | 25–29.9 | 23–24.9 |
| Obese | 30 and above | 25 and above |
BMI is a screening number. It does not separate muscle from fat, so athletes can read high, and it is not used for children, who need age-specific charts.
Frequently asked questions
Is BMI accurate?
It is a quick screening measure for adults, not a diagnosis. Waist size and other checks by a doctor give a fuller picture.
Can I use it for children?
No. Children and teenagers need BMI-for-age charts.
General information only, not medical advice.
Last updated 15 November 2026. Made by Criza Labs. Spotted a mistake? Tell us.