Enrollment
415
Pennsylvania · 2024-25 NCES data
High school (grades 9-12) · Allentown, PA
Building 21 Allentown
Federal NCES profile for Building 21 Allentown, including enrollment, faculty, free-lunch eligibility, demographics, and resource indicators - Resource Investment Index 36/100.
2024-25 NCES dataHigh school (grades 9-12)NCES 420228007623
👥 S:T ratio 41
📚 AP courses 10
🌟 Gifted program 70
🎓 Counselors 59
📋 Attendance 0
Scored 0–100 from federal NCES and CRDC indicators, resource allocation, not test scores. Full methodology →
The verdict
Building 21 Allentown earns 36/100 on the Resource Investment Index, with class sizes larger than 73% of Pennsylvania schools.
- #4 of 5
- high schools in Allentown · Resource Index
- 36
- Resource Index · Typical
- 14.8:1
- large classes for Pennsylvania
- 97.3%
- free-lunch eligible
Building 21 Allentown has class sizes larger than 73% of Pennsylvania schools. Computed live against every Pennsylvania school reporting to NCES.
By Resource Investment Index, Building 21 Allentown ranks #4 of 5 high schools in Allentown, PA.
School address
District: Allentown City Sd · Pennsylvania
NCES ID 420228007623 Verify on NCES CCD record →
Teachers (FTE)
28.0
Federal CCD staff survey
Students per teacher
14.8:1
vs 13.6:1 Pennsylvania avg
+9% vs state
Free-lunch eligible
97.3%
vs 58.1% Pennsylvania avg
+67% vs state
Student-teacher ratio in context
How Building 21 Allentown compares with Pennsylvania and U.S. medians
What stands out at Building 21 Allentown
Building 21 Allentown is a high-poverty, mid-sized high school in Allentown, Pennsylvania, enrolling 415 students.
Class loads run somewhat heavier than typical: 14.8:1 puts it in the larger third of Pennsylvania schools by student-teacher ratio.
Economic need runs somewhat above the state's typical profile, with 97.3% of students eligible for free meals.
With 415 students, its enrollment sits close to the Pennsylvania median campus size.
Its Resource Investment Index lands in the lower third of 2,889 scored Pennsylvania schools.
Against 538 statewide peers matched on enrollment and economic need, it ranks mid-pack at #240.
Its student body is predominantly Hispanic or Latino (81% of enrollment) (diversity index 33/100).
No Advanced Placement courses are reported for this campus in the federal data.
Counselor coverage is strong, about 208 students per counselor, inside the American School Counselor Association's recommended 250:1.
Chronic absenteeism is elevated: 65.1% of students missed 10% or more of school days (2021-22 Civil Rights Data Collection).
Its district draws 18.3% of revenue from federal sources, an above-typical federal share that tends to track a higher-need student population.
Among Allentown's high schools, it stands alongside Parkland Hs (3,279 students): Building 21 Allentown is smaller than that campus by headcount and runs leaner classes (14.8:1 vs 15.2:1).
Allentown City Sd also operates William Allen Hs (3,074 students) and Louis E Dieruff Hs (1,914 students) alongside Building 21 Allentown.
Sourced from NCES CCD, CRDC, and F-33 (federal records, not a quality verdict). How we source and compute this.
Source: National Center for Education Statistics Common Core of Data + CRDC + F-33 · 2024-25
How Building 21 Allentown compares
Building 21 Allentown on the metrics families compare, against Pennsylvania and U.S. means.
| Metric | This school | vs Pennsylvania | Pennsylvania avg | U.S. avg |
|---|---|---|---|---|
| Students per teacher | 14.8:1 | ▲ 9% | 13.6:1 | 15.7:1 |
| Free-lunch eligible | 97.3% | ▲ 67% | 58.1% | 51.7% |
| Enrollment | 415 | top 58% | - | - |
Source: NCES Common Core of Data School-level CCD + state/national means from Public School Universe · 2024-25
14.8:1
Leaner classes than 49% of US schools, a middle-of-the-pack class size.
415
Bigger than 50% of US schools by enrollment, mid-sized for the country.
Equity indicators (what these measure)
Economic need
97.3%
free-lunch eligible
- 67% 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
14.8:1
students per teacher
- 9% above state mean
Top 73% in Pennsylvania - lower ratio than 27% of state schools
Close to the 15:1 benchmark most often cited for individualized attention.
Engagement
65.1%
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
$15,572
per pupil, district-wide
- below Pennsylvania avg of $17,970
Somewhat below the U.S. average per-pupil spend; funding constraints may affect programs, facilities, and staffing.
Support staff
Counselors2.0 FTE
Per 208 students, the combined health-and-guidance staffing load for this school.
Discipline context
1
in-school suspensions + 14 out-of-school
Suspension rate: 0.2 per 100 students. Combined in-school and out-of-school rate: 3.6 per 100 students. Reported via the Civil Rights Data Collection.
Overview
- Common Core of Data (June 2026): enrollment, staffing, and the student-teacher ratio above.
- Civil Rights Data Collection: discipline counts and program access (AP, gifted, special education).
- F-33 School District Finance Survey: the district-wide per-pupil spending figures below.
Three separate federal collections, each on its own reporting cadence - which is why this school's numbers line up on a consistent basis against every other school and state on this site, rather than mixing figures pulled from different survey years.
Student demographics
Hispanic or Latino 81.2%
African American 9.4%
Two or More 5.1%
White 3.1%
Asian 1.0%
Native Hawaiian / Pacific Islander 0.2%
Largest group: Hispanic or Latino at 81.2% of enrollment.
Student-body diversity index 32.8/100
Simpson diversity index - at 32.8, Building 21 Allentown is less mixed than the Pennsylvania school average of 37.3.
Programs
AP program Not offered
Gifted & talented Yes
Funding & spending
District-wide per-pupil expenditure for Allentown City Sd, which includes Building 21 Allentown.
$15,572
Per student
-13%
vs Pennsylvania
Avg $17,970
-6%
vs U.S.
Avg $16,593
Revenue mix
Local 29.0%
State 52.7%
Federal 18.3%
Source: NCES F-33 School District Finance Survey District-level finance · FY 2021-22 Per-pupil expenditure reflects the district-wide average. Individual school budgets are not reported at the federal level.
How Building 21 Allentown Compares to District-Mates
| School | Enrollment | Economic Profile | Student-Teacher Ratio |
|---|---|---|---|
| William Allen Hs | Larger | Lower economic need | Higher S:T ratio |
| Louis E Dieruff Hs | Larger | Similar economic need | Higher S:T ratio |
| South Mountain Ms | Larger | Similar economic need | Similar S:T ratio |
| Francis D Raub Ms | Larger | Similar economic need | Higher S:T ratio |
| Brigadier General Anna Mae Hays El Sch | Larger | Similar economic need | Similar S:T ratio |
Comparisons are relative to Building 21 Allentown's own figures; each column derives from NCES Common Core of Data.
Other Schools in This District
- Enrollment
- 3,074
- Students per teacher
- 21.8:1
- Resource Index
- 38/100
- Enrollment
- 1,914
- Students per teacher
- 18.1:1
- Resource Index
- 48/100
- Enrollment
- 972
- Students per teacher
- 13.7:1
- Resource Index
- 38/100
- Enrollment
- 876
- Students per teacher
- 16.5:1
- Resource Index
- 36/100
- Enrollment
- 807
- Students per teacher
- 15.8:1
- Resource Index
- 17/100
Similar high schools in Allentown
4 comparable high schools (grades 9-12) serving the same city.
Parkland Hs
Standard public school
3,279 students 15.2:1 students per teacher
William Allen Hs
Standard public school
3,074 students 21.8:1 students per teacher
Louis E Dieruff Hs
Standard public school
1,914 students 18.1:1 students per teacher
Salisbury Shs
Standard public school
546 students 15.6:1 students per teacher
Similar high schools statewide
Matched by enrollment size and by staffing ratio across all of Pennsylvania, not just this city - a different peer set than the local comparisons above.
Similar enrollment (~415 students)
Similar student-teacher ratio (~14.8:1)
Next steps
Verify locally before acting on Building 21 Allentown's federal record.
- Compare Building 21 Allentown against another school. Compare schools
- Allentown City Sd's spending and staffing shape this school. District profile
- Confirm current enrollment and boundaries with the school. Choosing guide
Federal record (CCD 2024-25, CRDC 2021-22) - PlainSchools assigns no subjective rating; the composite quality score is a transparent, reproducible index computed from this cited federal data.
Frequently asked questions about Building 21 Allentown
How many students attend Building 21 Allentown?
Building 21 Allentown has 415 students enrolled. It is a high school in Allentown, PA.
What is the student-teacher ratio at Building 21 Allentown?
The student-teacher ratio at Building 21 Allentown is 14.8:1, which is 9% higher than the Pennsylvania average of 13.6:1 and 6% lower than the national average of 15.7:1.
What percentage of students receive free lunch at Building 21 Allentown?
97.3% of students at Building 21 Allentown are eligible for free lunch, compared to the Pennsylvania average of 58.1%.
What is the racial and ethnic makeup of Building 21 Allentown?
The largest demographic group at Building 21 Allentown is Hispanic or Latino at 81.2% of enrollment, in Allentown, PA.
What is the Resource Investment Index for Building 21 Allentown?
Building 21 Allentown has a Resource Investment Index of 36/100 (typical reported resources relative to schools nationally) based on 5 factors: student-teacher ratio, counselor availability, attendance rates. Not a test-score or academic measure (national median ~41/100, see methodology).
How does Building 21 Allentown rank among high schools in Allentown?
By Resource Investment Index, Building 21 Allentown ranks #4 of 5 high schools in Allentown, 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 Allentown on the city page.
Is Building 21 Allentown a good school?
Building 21 Allentown earns 36/100 on the Resource Investment Index, with class sizes larger than 73% of Pennsylvania schools. This is a resource snapshot, not an academic rating; see the Resource Investment Index question above for what the number does and doesn't measure.
What other schools are in Allentown City Sd?
Besides Building 21 Allentown, Allentown City Sd also operates William Allen Hs (3,074 students), Louis E Dieruff Hs (1,914 students), and South Mountain Ms (972 students). See the Allentown City Sd district page for the complete list.
Related tools
Every figure on PlainSchools is rendered directly from the source NCES, CRDC and F-33 federal records, no number is typed in by an editor. Each school's figures reflect its most recent NCES/CRDC submission on file. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error. Data current as of June 2026.