BMI Calculator

BMI or Body Mass Index is a globally acknowledged, scientific method of measuring obesity. Recommended by the WHO (World Health Organization), it is a simple index of weight- for- height, which is used to classify underweight, normal, overweight and obese adults along with their level of associated health risks. It is calculated by dividing the weight in kilograms by the square of an individual’s height in meters. The classification of Underweight, Normal Overweight and Obese according to BMI is given in the table below (Ref: Misra A. Body Composition and the metabolic syndrome in Asian Indians: A saga of multiple adversities. Natl Medical J India 2003;16(1):3-7 )



Classification of adults according to BMI


Classification 

Popular Description 

BMI (kg/m2)

Risk of co-morbidities

Underweight 

Thin 

<18.5 

Low (but risk of other clinical problems increased)

Normal range 

Normal 

18.5 - 22.9 

Average

Overweight 

 

23 – 24.9

 

Pre-obese 

Overweight 

25 - 29.9 

Increased

Obese Class I 

Obese 

30.0 - 34.9 

Moderate

Obese Class II 

Obese 

35.0 - 39.9 

Severe

Obese Class III 

Morbidly Obese 

> =  40.0 

Very severe