At The Hill, students are enrolled in "forms," which is the traditional English term equivalent to "grade levels."
Third form = 9th grade
Fourth form = 10th grade
Fifth form = 11th grade
Sixth form = 12th grade
This class system first was adopted in 1880 by the School's second headmaster, John Meigs, the son of the School founder the Reverend Matthew Meigs. From 1880 until 1998, when The Hill became coed, the School also included a second form (eighth grade).