When a child weighs more than a normal child weighs at its age and height then the child is either considered overweight or obese The Body Mass Index is an indicator for which there is a formula which is BMI = [weight / (height x height)] x 703. Unlike adults where there is a standard BMI to determine whether the adult is obese/ overweight or underweight for children it is different. If a 10 year old boy has a BMI of 23 he will be considered obese but not a fifteen year old with the same BMI. It is best left to the expert calculators which make use of several factors when determining the BMI of a child. One needs to just feed in the data in those calculators.
Once the BMI is obtained it could be compared to a chart that is worked by experts which is looks something like this::
Underweight: Less than the 5th percentile
Normal weight:: 5th percentile to less than the 85th percentile
Overweight: 85th to less than the 95th percentile
Obese: Equal to or greater than the 95th percentile
