As of the 2022-2023 school year, there are 2 basic lengths of courses at Chelsea High School: semester, and full year.
- Semester 1 courses end at the end of quarter 2 and require both quarter and final grades at the end of quarter 2. If a full year course is broken into S1/S2 pairs, the S1 pair of a full year course will need both quarter and final grades at the end of quarter 2.
- Semester 2, S2 pairs of full year courses, AND full year courses that are NOT broken into S1/S2 pairs (like most AP courses) end quarter 4 and require both quarter and final grades at the end of quarter 4.