BMI Calculator

What is a healthy weight

BMI Calculator

Health risks from being overweight

These risks are linked with overweight and obese adults

Adults whose BMI is greater than 25 (overweight) or with a BMI greater than 30 (obese) have an expanded risk for varied diseases and health conditions, including,:

BMI History

Body Mass Index Prime is method of using the results of the BMI calculations to quickly and easily rank a person into a category. Eg:
  • BMI Prime < 0.74 = Underweight.
  • BMI Prime > 0.74 and < 1.00 = Optimal weight
  • BMI Prime > 1 = Overweight
BMI, sometimes known as the Quetelet index, is a measure used to estimate a person's body shape based upon a person' weight and height. It originated in Belguim around the 1840's by Adolphe Quetelet. It is a simple calculation based on the individual's body weight divided by the square of their height.

The maths

This is how BMI is calculated
  • BMI = weight(kilograms) / height2 (metres2)         (Metric Units)
  • BMI = 703 . weight(pounds) / height2 (inches2)         (Imperial Units)

BMI limitations

BMI is proportional to the mass and inversely proportional to the square of the height. So, if all body dimensions double, and mass scales naturally with the cube of the height, then BMI doubles instead of remaining the same. This results in taller people having a reported BMI that is uncharacteristically high, compared to their actual body fat levels.
See wikipedia.org/wiki/Body_mass_index#Limitationsinfomation.