- Enrollment
- 3,463
- Students per teacher
- 18.9:1
- Resource Index
- 31/100
High school (grades 9-12) · Philadelphia, PA
Building 21
Federal NCES profile for Building 21, including enrollment, faculty, free-lunch eligibility, demographics, and resource indicators - Resource Investment Index 40/100.
2024-25 NCES dataHigh school (grades 9-12)NCES 421899007534
👥 S:T ratio 26
🌟 Gifted program 70
🎓 Counselors 63
📋 Attendance 0
Scored 0–100 from federal NCES and CRDC indicators, resource allocation, not test scores. Full methodology →
The verdict
Building 21 earns 40/100 on the Resource Investment Index, with class sizes larger than 96% of Pennsylvania schools.
- #28 of 57
- high schools in Philadelphia · Resource Index
- 40
- Resource Index · Typical
- 18.6:1
- large classes for Pennsylvania
- 100.0%
- free-lunch eligible
Building 21 has class sizes larger than 96% of Pennsylvania schools. Computed live against every Pennsylvania school reporting to NCES.
By Resource Investment Index, Building 21 ranks #28 of 57 high schools in Philadelphia, PA.
School address
District: Philadelphia City Sd · Pennsylvania
NCES ID 421899007534 Verify on NCES CCD record →
CCD year-over-year · 2022-23 → 2023-24
-6 students YoY
Building 21 held near 382 students from 2022-23 to 2023-24 (-6 headcount).
Teacher FTE added 20.2 → 25.2 across the same CCD years.
Source: NCES Common Core of Data public-school universe (2022-23, 2023-24).
Steady CCD campus
-6 students YoY 421899007534 · Philadelphia, PA High · SMALL · TRAD
371 enr · 18.6:1 · 100.0% lunch · RII 40
Nearest enrollment peer: Northeast Hs (3,463 students)
Building 21 held near 382 students from 2022-23 to 2023-24 (-6 headcount). Teacher FTE added 20.2 → 25.2 across the same CCD years. Read with this school → · District book → · Pennsylvania schools → · Find another →
Building 21 in the enrollment neighbourhood
Fall enrollment among this campus and nearest district peers
- Northeast Hs
Northeast Hs
3,463 students
- Lincoln Hs
Lincoln Hs
2,472 students
- Central Hs
Central Hs
2,329 students
- Northeast Comm
Northeast Community Propel Academy
1,783 students
- Mayfair Sch
Mayfair Sch
1,763 students
- This school 371
Building 21
371 students
What this shows Building 21 reports 371 students on the CCD universe file.
How Building 21 compares
Building 21 held steady on CCD headcount: ratios and free-lunch share vs Pennsylvania and U.S. means.
| Metric | This school | vs Pennsylvania | Pennsylvania avg | U.S. avg |
|---|---|---|---|---|
| Students per teacher | 18.6:1 | ▲ 37% | 13.6:1 | 15.7:1 |
| Free-lunch eligible | 100.0% | ▲ 72% | 58.1% | 51.7% |
| Enrollment | 371 | top 66% | - | - |
Source: NCES Common Core of Data School-level CCD + state/national means from Public School Universe · 2024-25
18.6:1
Leaner classes than 22% of US schools, heavier class loads than most.
371
Bigger than 43% of US schools by enrollment, mid-sized for the country.
Equity indicators methodology
Economic need
100.0%
free-lunch eligible
- 72% above the Pennsylvania average of 58.1%
Above the 40% Title I schoolwide threshold; federal funds support the whole school, not individual students.
Staffing depth
18.6:1
students per teacher
- 37% above state mean
Top 96% in Pennsylvania - lower ratio than 4% of state schools
Between 16:1 and 20:1, squarely in the typical U.S. public-school staffing range.
Engagement
43.1%
chronically absent (missed 10%+ of school days)
At or above 20%, the commonly used threshold for "high" chronic absenteeism, signaling significant barriers to regular attendance.
Funding equity
$18,329
per pupil, district-wide
- below Pennsylvania avg of $18,725
Close to the U.S. public-school average per-pupil spend.
Support staff
Counselors2.0 FTE
Per 186 students, the combined health-and-guidance staffing load for this school.
Discipline context
0
in-school suspensions + 23 out-of-school
Suspension rate: 0.0 per 100 students. Combined in-school and out-of-school rate: 6.2 per 100 students. Reported via the Civil Rights Data Collection.
Student demographics
African American 91.4%
Hispanic or Latino 5.4%
Two or More 2.2%
Asian 0.8%
White 0.3%
Largest group: African American at 91.4% of enrollment.
Student-body diversity index 16.1/100
Simpson diversity index - at 16.1, Building 21 is less mixed than the Pennsylvania school average of 37.3.
Programs
AP program Not offered
Gifted & talented Yes
District finance for Philadelphia City Sd reports $18,329 per pupil (NCES F-33) - open the district page for the full revenue mix.
How Building 21 Compares to District-Mates
| School | Enrollment | Economic Profile | Student-Teacher Ratio |
|---|---|---|---|
| Northeast Hs | Larger | Similar economic need | Similar S:T ratio |
| Lincoln Hs | Larger | Similar economic need | Lower S:T ratio |
| Central Hs | Larger | Similar economic need | Higher S:T ratio |
| Northeast Community Propel Academy | Larger | Similar economic need | Higher S:T ratio |
| Mayfair Sch | Larger | Similar economic need | Higher S:T ratio |
Comparisons are relative to Building 21's own figures; each column derives from NCES Common Core of Data.
Other Schools in This District
- Enrollment
- 2,472
- Students per teacher
- 17:1
- Resource Index
- 34/100
- Enrollment
- 2,329
- Students per teacher
- 20.1:1
- Resource Index
- 45/100
- Enrollment
- 1,783
- Students per teacher
- 22.6:1
- Resource Index
- 21/100
- Enrollment
- 1,763
- Students per teacher
- 21:1
- Resource Index
- 40/100
Similar high schools in Philadelphia
6 comparable high schools (grades 9-12) serving the same city.
Northeast Hs
Standard public school
3,463 students 18.9:1 students per teacher
Lincoln Hs
Standard public school
2,472 students 17:1 students per teacher
Central Hs
Standard public school
2,329 students 20.1:1 students per teacher
Washington George Hs
Standard public school
1,755 students 15.8:1 students per teacher
Franklin Towne Chs
Standard public school
1,292 students 18.5:1 students per teacher
Fels Samuel Hs
Standard public school
1,255 students 17.7:1 students per teacher
Nationwide high schools with similar size or staffing
Out-of-state peers matched by enrollment and by student-teacher ratio, not the same-city or same-district lists above.
Similar enrollment (~371 students)
Similar student-teacher ratio (~18.6:1)
Frequently asked questions about Building 21
How many students attend Building 21?
Building 21 has 371 students enrolled. It is a high school in Philadelphia, PA. CCD year-over-year: 388 (2022-23) → 382 (2023-24), nearly flat (-6).
What is the student-teacher ratio at Building 21?
The student-teacher ratio at Building 21 is 18.6:1, which is 37% higher than the Pennsylvania average of 13.6:1 and 18% higher than the national average of 15.7:1.
What percentage of students receive free lunch at Building 21?
100.0% of students at Building 21 are eligible for free lunch, compared to the Pennsylvania average of 58.1%.
What is the racial and ethnic makeup of Building 21?
The largest demographic group at Building 21 is African American at 91.4% of enrollment, in Philadelphia, PA.
What is the Resource Investment Index for Building 21?
Building 21 has a Resource Investment Index of 40/100 (typical reported resources relative to schools nationally) based on 4 factors: student-teacher ratio, gifted-program reporting, counselor availability, chronic absenteeism. Not a test-score or academic measure (national median ~41/100, see methodology).
How does Building 21 rank among high schools in Philadelphia?
By Resource Investment Index, Building 21 ranks #28 of 57 high schools in Philadelphia, PA. This compares federal resource and staffing data among local peers; it is not a test-score or academic ranking. See all high schools in Philadelphia on the city page.
What other schools are in Philadelphia City Sd?
Besides Building 21, Philadelphia City Sd also operates Northeast Hs (3,463 students), Lincoln Hs (2,472 students), and Central Hs (2,329 students). See the Philadelphia City Sd district page for the complete list.