Ninth grade is the biggest class in American public schools. Which grade is the smallest?

Ninth grade is the largest class in American public schools. In the 2024-25 school year, 3,965,890 students were enrolled in ninth grade across the 50 states and Washington, D.C., according to allk12's analysis of federal enrollment data. First grade was the smallest, with 3,415,642 students.

Public school enrollment by grade in the 50 states and Washington, D.C. Excludes about 49,500 students not assigned to a grade. Source: allk12 analysis of NCES Common Core of Data, 2024-25.

Why ninth grade is so big

Ninth grade had 266,545 more students than eighth grade, a jump of about 7%. That pattern is old. Education researchers call it the ninth-grade bulge. Much of it comes from students who fall short on credits and repeat ninth grade. Chalkbeat reported in 2022 that freshman classes grew in many states after the pandemic because more ninth graders were held back. In Fort Worth, Texas, about 990 of 7,300 freshmen were repeating the grade.

After ninth grade, each class gets a little smaller through 12th grade, which had 3,781,294 students.

The youngest grades are smaller

At the other end, the early elementary grades are smaller than the middle school grades. Grades 1 through 3 enrolled 10,579,891 students, compared with 10,966,469 in grades 6 through 8, a gap of 3.5%. The gap is much larger in some states. We break it down state by state in our study of where early grades are smaller than middle school.

Public pre-K is much smaller than any other grade, at 1,366,790 children. Most states do not offer it to every child.

Sources
Enrollment by grade from allk12's analysis of National Center for Education Statistics (NCES) Common Core of Data, 2024-25.
Chalkbeat: After a surge in ninth graders held back, schools step up support
Education Week: 9th Grade Bulge