Are you HWP ?
This body mass calculation is based on the ratio of weight (in kg) to height (in meters) squared. For most people, this ratio should be between 20 and 25*. If you are between 25 and 30 you are considered overweight, and if over 30 you are considered obese.
* This was the case when this formula appeared in 1992. Current findings are a bit more forgiving at the high end, particularly for people over 35. Also, if you are a bodybuilder, wrestler, etc it is reasonable to be out of the "ideal" range.