Does body mass and weight matter for dose size?

Most medications for children are dosed according to age, body weight (mg/kg) or body surface area (BSA) (mg/m2) or a combination of these factors. When giving medication to children, be sure to follow the instructions on the drug label to avoid overdosing.
References:
http://patient.info/doctor/prescribing-for-children
http://www.fda.gov/Drugs/ResourcesForYou/Consumers/ucm312776.htm