#1 Private Schools with the Smallest Classes in Boulder County, CO
Longmont Christian School
Christian school (nondenominational) · Grades Pre-K–8
3.6 students per teacher
Longmont, CO
A+Overall grade47 students4 students per teacher
2026 lists
Private Schools with the Smallest Classes in Boulder County, CO
Private schools in Boulder County, CO with the fewest students per teacher (not counting preschools and special education schools). Top 15 of 15 schools.
#2 Private Schools with the Smallest Classes in Boulder County, CO
Bixby School
Independent school · Grades Pre-K–5
3.7 students per teacher
Boulder, CO
A+Overall grade93 students4 students per teacher
#3 Private Schools with the Smallest Classes in Boulder County, CO
Boulder Valley Waldorf School
Independent school · Grades Pre-K–8
4.9 students per teacher
Niwot, CO
A-Overall grade95 students5 students per teacher
#4 Private Schools with the Smallest Classes in Boulder County, 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
#5 Private Schools with the Smallest Classes in Boulder County, 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
#6 Private Schools with the Smallest Classes in Boulder County, CO
Mapleton Montessori School
Montessori school · Ungraded
5.9 students per teacher
Boulder, CO
A-Overall grade48 students6 students per teacher
#7 Private Schools with the Smallest Classes in Boulder County, 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
#8 Private Schools with the Smallest Classes in Boulder County, 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
#9 Private Schools with the Smallest Classes in Boulder County, CO
Watershed School
Independent school · Grades 6–12
6.7 students per teacher
Boulder, CO
BOverall grade114 students7 students per teacher
#10 Private Schools with the Smallest Classes in Boulder County, CO
Rocky Mountain Christian Academy
Christian school (nondenominational) · Grades Pre-K–8
7.3 students per teacher
Niwot, CO
A-Overall grade98 students7 students per teacher
#11 Private Schools with the Smallest Classes in Boulder County, CO
Jarrow Montessori School
Montessori school · Grades Pre-K–6
7.5 students per teacher
Boulder, CO
BOverall grade70 students8 students per teacher
#12 Private Schools with the Smallest Classes in Boulder County, CO
St. Louis Catholic School
Parish school · Grades Pre-K–8
7.8 students per teacher
Louisville, CO
A+Overall grade93 students8 students per teacher
#13 Private Schools with the Smallest Classes in Boulder County, 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
#14 Private Schools with the Smallest Classes in Boulder County, CO
St. John the Baptist Catholic School
Diocesan school · Grades Pre-K–8
10.3 students per teacher
Longmont, CO
A+Overall grade185 students10 students per teacher
#15 Private Schools with the Smallest Classes in Boulder County, 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.