The BMI is a poor measure for your ideal weight due to differences in body types; however, it is a great tool to establish a start point, and then to track your progress.
A BMI that is greater than 30 is considered OBESE. The only case where this would not be applicable would be in a very fit individual with a large lean body mass, an example being a body-builder or professional athlete. So if your body mass index is 30 or greater and you don’t see at least a hint of a six-pack, then the BMI is most likely applicable.
There are no standardized tables for children, similar to the table for adults. A child’s BMI is defined as a percentile rank based on age and sex. A healthy weight for a child is a weight that is between the 5th and 85th percentile for age.