Well, it depends. For most people, hair strands get to three feet long before they fall out. Children's hair grows faster than adults' hair does. Everyone's hair grows faster in summer than in winter. Hair also grows faster in the morning than at night.
Hair grows faster on the crown than on the sides of the head.
Diet and health affect hair growth, but haircuts and shaving make no difference. You grow about seven miles of new hair a year. What's on top of your head can take a lot of shapes and styles. And believe it or not, that's been the fashion throughout human history. In ancient Egypt, both men and women shaved their heads.