The average height of a 15 year old girl? I just want to know what people think. My Measurements are 164 cm (6.4)Average makes no sense. However, the Center for Disease Control says:64 inch or 5-foot 4-inch girls are considered normal. To reach the 97th percentile, a 15-year-old girl needs only 69 inches. The 59-inch or 4-foot-11-inch girl is in third percentile in height.