See your BMI on a chart

Chart your BMI against the national average

Check my BMI

Health dangers from being overweight

These dangers are associated with overweight and obese adults

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

BMI Origins

B.M.I. Prime is simple way of defining a single figure that is not immedieately related to any other units of measurement, but which can 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
This app will calculate your body mass index and tell you if you are underweight, overweight or if your weight is optimal. Just enter your vital statistics and click the button. Your result will be shown on a graph for you.

The maths

BMI is defined by the following formula
  • 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.