There is no 'average' height for 11-16 year olds.
This is because people have different growth rates of puberty, for example, a 11 year old girl could be 4'10" while a 16 year old boy could be 6'2", but the average heights for adults are around
5'10" (males) and
5'5" (females)
to give a comparison im a 15 year old guy and im 5'7