School Age Calculator USA
www.schoolwix.com › usStudents start High School in 9th Grade in Freshman year at 13 or 14 years old. How Old Are You in Each School Grade? High School Graduation Students in the USA will usually commence their final year, 12th Grade / Senior Year, at the age of 17 or 18 years old. At the end of the school yea most students are 18 years of age.