What is the average weight range for a 13-year-old 5' 6 boy?

Average Weight120 lbs. is a little over weight for a 13-year-old, if anything, but if you are fit and healthy and eat a good diet I wouldn't worry about it.

See the Related Link for "Heigh/weight charts" to the bottom for the answer.

AnswerA 5'6" 13 year old would, on average, weigh between 132 and 154 pounds, (9st 6lbs to 11st 4lbs)

Because of the differences in maturity at this age a girl would tend to weigh more than a boy of the same height. A healthy 13 year old should weight 145-178

AnswerAt that age you would need the child's gender to make a determination. Here is a link to the 'official' charts of what is 'normal' in the US http://www.cdc.gov/nchs/about/major/nhanes/growthcharts/clinical_charts.htm