1. Height and weight development indicators The height and weight of an 11-month-old baby is one of the issues that parents are most concerned about. During this period, the height and weight of both male and female babies have increased significantly, but the specific figures should be considered based on the situation of your own child. Generally speaking, the average height of an 11-month-old male baby is about 72.2 cm and the average weight is about 9.1 kg; the average height of a female baby is about 70.8 cm and 8.7 kg respectively.