BMI Calculator
Body mass index from weight and height, with the WHO bands and the lower Asian screening cut-offs.
Enter the values and press Calculate.
Your result will show here.
About this calculator
Body mass index divides weight by the square of height. It is a screening ratio, not a measure of health. Two people with the same BMI can have different fitness, muscle, and fat.
The World Health Organization bands used on this page put overweight at 25 and obesity at 30. Several Indian screening references start the higher-risk band at 23. The calculator shows both so the difference is visible instead of hidden inside one word.
Enter weight in kilograms and height in centimetres. A height in feet has to be converted first. 5 feet 7 inches is 170 centimetres only as a rough memory; measure rather than guess.
Do not use the result to start, stop, or change a diet or a medicine. If the number worries you, ask a doctor who can see more than a ratio.
BMI formula
BMI = weight in kilograms / (height in metres)² Height in metres = centimetres ÷ 100. WHO bands used here: under 18.5 underweight, 18.5 to 24.9 normal, 25 to 29.9 overweight, 30 and above obese. Asian screening bands shown beside them: under 18.5, 18.5 to 22.9, 23 to 24.9, and 25 and above.
Example: 70 kg and 170 cm
70 ÷ (1.70 × 1.70) = 24.2.
That sits in the WHO normal band and in the Asian overweight screening band, because those scales do not share the same line at 23.
70 kg and 170 cm
WHO and Asian labels can differ.
24.2
How to use
- Enter weight in kilograms.
- Enter height in centimetres.
- Press Calculate and read both labels. They are screening bands, not a diagnosis.
Important notes
- BMI does not measure body fat, muscle, or fitness.
- It is a weak guide for children, athletes, and pregnancy.
- A clinician uses more than this number.
- The Asian cut-offs are for screening context. They do not replace a doctor.
FAQ
What is a normal BMI?
On the WHO bands used here, 18.5 to 24.9 is labelled normal. Asian screening often treats 23 and above differently. Both labels are shown.
Does BMI measure fat?
No. It is weight over height squared. It cannot see muscle or fat.
Is this for children?
No. Child BMI uses age-specific charts. This page is a simple adult-style ratio.
Which unit is height?
Centimetres. Convert feet and inches before you type, or the result will be wrong.
Disclaimer
Results are estimates for general information. Verify important decisions with an appropriate professional or official source. This BMI figure is not a medical diagnosis.
Last updated 5 October 2026.