[@NuttsnBolts] Some districts do 5-8th grade as middle school in America, other districts do 7-8th and there's an intermediary school (5-6) between Elementary school (1-4) and Middle School (7-8). Highschool is almost unanimously allocated to grades 9-12. Generally, kids start off 1st grade at the ages 5-6, transcribing to High school, freshmen are usually around 14-15 years old, seniors being 17-18.