#1 Private Schools with the Smallest Classes in Boulder, CO
Bixby School
Independent school · Grades Pre-K–5
3.7 students per teacher
Boulder, CO
A+Overall grade93 students4 students per teacher
2026 lists
Private Schools with the Smallest Classes in Boulder, CO
Private schools in Boulder, CO with the fewest students per teacher (not counting preschools and special education schools). Top 10 of 10 schools.
#2 Private Schools with the Smallest Classes in Boulder, CO
Shining Mtn. Waldorf High School
Independent school · Grades Pre-K–12
5.4 students per teacher
Boulder, CO
AOverall grade188 students5 students per teacher
#3 Private Schools with the Smallest Classes in Boulder, CO
Boulder Country Day School
Independent school · Grades Pre-K–8
5.7 students per teacher
Boulder, CO
B+Overall grade281 students6 students per teacher
#4 Private Schools with the Smallest Classes in Boulder, CO
Mapleton Montessori School
Montessori school · Ungraded
5.9 students per teacher
Boulder, CO
A-Overall grade48 students6 students per teacher
#5 Private Schools with the Smallest Classes in Boulder, CO
Sacred Heart of Jesus School
Parish school · Grades Pre-K–8
6.3 students per teacher
Boulder, CO
A+Overall grade169 students6 students per teacher
#6 Private Schools with the Smallest Classes in Boulder, CO
Mountain Shadows Montessori School
Montessori school · Grades Pre-K–4
6.3 students per teacher
Boulder, CO
A-Overall grade44 students6 students per teacher
#7 Private Schools with the Smallest Classes in Boulder, CO
Watershed School
Independent school · Grades 6–12
6.7 students per teacher
Boulder, CO
BOverall grade114 students7 students per teacher
#8 Private Schools with the Smallest Classes in Boulder, CO
Jarrow Montessori School
Montessori school · Grades Pre-K–6
7.5 students per teacher
Boulder, CO
BOverall grade70 students8 students per teacher
#9 Private Schools with the Smallest Classes in Boulder, CO
Shining Mountain Waldorf School
Independent school · Grades Pre-K–12
9.9 students per teacher
Boulder, CO
B-Overall grade170 students10 students per teacher
#10 Private Schools with the Smallest Classes in Boulder, CO
Friends School
Independent school · Grades Pre-K–8
134 students per teacher
Boulder, CO
B-Overall grade134 students
From official public records, updated October 2026.