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Magnet SchoolHigh

Building 21

6501 Limekiln Pike, Philadelphia, PA 19138

DSchola Grade
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Grades
9–12
High
Students
371
Enrolled 2024–25
Students per teacher
20.5 : 1
Full-time teachers
District
Philadelphia City SD
Philadelphia County

Schola Grade D · Below average

Letter grade (A–F) · compared with 629 Pennsylvania high schools · How we grade
Test scores22% proficient in math & reading
9thpercentile
Equity15% of low-income students proficient
6thpercentile
Attendance33% chronically absent
29thpercentile
Graduation rate87% graduate in 4 years
25thpercentile
College readinessAt least 6% take AP, IB or dual-enrollment courses
19thpercentile
Class size20.5 students per teacher
4thpercentile

Percentiles compare this school with other Pennsylvania high schools; the line marks the middle. Data: test scores 2021–22, graduation and absenteeism 2022–23 (U.S. Department of Education, EDFacts); coursework 2023–24 (Civil Rights Data Collection); staffing 2024–25 (NCES).

About Building 21

Building 21 is a magnet high school in Philadelphia, Pennsylvania, serving grades 9–12. It is part of Philadelphia City SD. The school is located in a large city in Philadelphia County.

In the 2024–25 school year, 371 students were enrolled, with about 20.5 students for every full-time teacher. That ratio is larger than the typical Pennsylvania high school (13.3 students per teacher). Its Schola Grade is D (below average), compared with 629 Pennsylvania high schools.

Grades & enrollment

Students per grade, 2024–25Grades 9–12

Location & nearby schools

6501 Limekiln Pike
Philadelphia, PA 19138
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School details

Type
Magnet School · What this means
Level
High
Grades offered
9–12
Enrollment (2024–25)
371 students
Students per teacher
20.5 to 1
Charter school
No
Magnet school
Yes
Virtual learning
Offers virtual courses
Locale
City — Large
School district
Philadelphia City SD
County
Philadelphia County
NCES school ID
421899007534

Schools near Building 21

All 420 schools in Philadelphia →
Girls HS
Public · Grades 9–12 · 592 students
B1.1 mi
Central HS
Public · Grades 9–12 · 2,329 students
A1.1 mi

School data comes from the U.S. Department of Education: the National Center for Education Statistics (NCES) Common Core of Data and EDGE school locations (2024–25) and Private School Survey (2023–24), the Civil Rights Data Collection (2023–24), and EDFacts (test results 2021–22; graduation and chronic absenteeism 2022–23), plus other public sources. Please contact the school to confirm enrollment, programs, and other details. How we source data.