Your height. If you've completed puberty you aren't likely to grow taller. Girls complete puberty by ages 15 to 17 & for boys it is by ages 16 to 17. However, if one enters puberty late, they will usually also complete it late. Our height is largely determined by genetics (our parents' height). If you are healthy (no unusual causes for stunted growth/ smaller stature) then there is not a way to become taller.