In American schools, academic years are referred to as "grades," with the 12-year span—corresponding to the period from the first year of elementary school through the third year of high school in Japan—covering grades 1 through 12. Compulsory education in the United States begins at an age equivalent to the final year of kindergarten in Japan. This level is known as "Kindergarten" (or "K"), and the span from grade K through 12 constitutes the standard period of compulsory education, commonly abbreviated as "K–12."
The 12-year structure covering elementary, middle, and high school varies by region. A common arrangement consists of grades 1–5 for elementary school, grades 6–8 for middle school, and grades 9–12 for high school.
Each of the four years of high school has a specific name: Grade 9 is called "Freshman," Grade 10 "Sophomore," Grade 11 "Junior," and Grade 12 "Senior."