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Body Mass Index: BMI Calculator

Body Mass Index (BMI) is a simple index of weight-for-height that is commonly used to classify overweight and obesity in adults. BMI is a calculated value achieved by dividing the weight (expressed in kg) by the square of the height (expressed in metres).

The International Classification of adult underweight, overweight and obesity according to BMI by the World Health Organisation is as follows:

BMI(kg/m2) Classification 
 < 18.5  Underweight
 18.5 - 24.99  Normal range
 25 - 29.99  Overweight
 30 - 34.99  Obese Class I
 35 - 39.99  Obese  Class II
 Above 40  Obese  Class III

Calculating your BMI

Enter your details:
Height: Centimeters
 
Weight: Kilograms
Your BMI:

Imperial mesurement calculator

Use the BMI as a general guide but remember there may be reasons to modify the interpretation and you should discuss this with your doctor if you were concerned.

When BMI can be Misleading

  1. In Athletes: The BMI can be misleading in athletes (such a body builders) who have a low body fat percentage, but deliver an excessive BMI as they have a significant increase in muscle mass. As the index is a calculation of weight and height alone, it assumes that the increase is due entirely to body fat.
  2. In Children: The BMI can be misleading in children, as body fatness changes over the years as they grow, and girls and boys also differ in their body fatness as they mature. In children it is better to express weight as a percentile value, in which it is compared to others at the same age and sex.
  3. In Ethnic Populations: For some ethnic populations, such as Asian and Pacific populations, the BMI values may need to be modified. For Asian populations, a BMI greater than 23 can be regarded as overweight and a BMI greater than 27.5 can be regarded as obese.

Volunteer - Research Participants Needed

The Centre for Obesity Research and Education (CORE) is always looking for people who are willing to donate their time and participate in studies in the area of obesity. Our team conducts research projects to improve knowledge leading to better management & treatment options.

More information about volunteering.