Enrollment
251
California · 2024-25 NCES data
2024-25 NCES data Elementary school (grades K-5) NCES 063132004836
Armstrong Elementary — Diamond Bar, CA
Federal NCES profile for Armstrong Elementary, including enrollment, faculty, free-lunch eligibility, demographics, and resource indicators — Resource Investment Index 37/100.
👥 Class size 26
🌟 Gifted program 70
🎓 Counselors 50
📋 Attendance 0
How this works: Each indicator above is scored 0–100 from federal NCES and CRDC data, then averaged into the Resource Investment Index. This measures resource allocation — staffing, programs, and support services — not standardized test scores or academic outcomes. Full methodology →
School address
District: Pomona Unified · California
Public location data per NCES (National Center for Education Statistics) Common Core of Data. Verify the school's current address on the NCES CCD record.
Teachers (FTE)
14.0
Federal CCD staff survey
Students per teacher
18.4:1
vs 21.6:1 California avg
-15% vs state
Free-lunch eligible
49.4%
vs 55.5% California avg
-11% vs state
Student-teacher ratio in context
How Armstrong Elementary compares with California and U.S. medians
The federal record — no proprietary index, no editorial formula.
PlainSchools publishes the actual federal measurements — enrollment, staffing, demographics, discipline, and finance — straight from the NCES Common Core of Data, CRDC, and F-33 surveys. No composite rating, no opinion-based score on top. You get the same raw numbers researchers and policymakers use, with benchmarks, spending context, and equity indicators computed from the same federal datasets. Full methodology linked below.
What this school's NCES data tells you
Armstrong Elementary reports 251 enrolled students to the National Center for Education Statistics (NCES) alongside 14.0 full-time-equivalent teachers, producing a 18.4:1 student-teacher ratio. That figure sits 15% below the California state mean of 21.6:1, signalling more teacher attention per pupil than the state benchmark. Against the national 2024-25 average of 15.9:1, it is 16% higher, a useful calibration for families comparing districts across state lines.
Title I and federal lunch eligibility offer another window into the student body: 49.4% of pupils qualify for free meals, a proxy for household income that federal programs use to direct funding. The free-lunch share is 11% below the California average and 5% below the national baseline. Counselor coverage works out to roughly 251 students per counselor, above the ASCA-recommended ceiling of 250:1. Chronic absenteeism — missing 10% or more of school days — stands at 47.0% according to the 2021-22 Civil Rights Data Collection.
On the finance side, the surrounding Pomona Unified spends $21,992 per pupil district-wide, above the California average of $18,039 and above the national average of $19,490. Revenue comes 21.6% from local sources (property taxes), 60.9% from the state, and 17.6% from federal programs per the NCES F-33 finance survey. Taken together, these measurements produce a Resource Investment Index of 37/100 (F), calculated from 4 distinct NCES and CRDC indicators measuring resource allocation rather than academic outcomes.
Source: National Center for Education Statistics Common Core of Data + CRDC + F-33 · 2024-25
How Armstrong Elementary compares
Cross-validating school-level NCES values against California state and U.S. national means lets readers see whether this school is an outlier or in line with peers.
| Metric | This school | vs California | California avg | U.S. avg |
|---|---|---|---|---|
| Students per teacher | 18.4:1 | ▼ 15% | 21.6:1 | 15.9:1 |
| Free-lunch eligible | 49.4% | ▼ 11% | 55.5% | 51.8% |
| Enrollment | 251 | top 21% | — | — |
Source: NCES Common Core of Data School-level CCD + state/national means from Public School Universe · 2024-25
What the federal data reveals about equity at this school
Federal measurements — not ratings — surface the resource and opportunity picture. Below are the indicators that researchers, civil-rights monitors, and funding formulas use to assess equity.
Economic need
49.4%
free-lunch eligible
— 11% below the California average of 55.5%
Above the 40% Title I schoolwide threshold — federal funds support the whole school, not individual students.
Staffing depth
18.4:1
students per teacher
— 15% below state mean
Top 19% in California — lower ratio than 81% of state schools
Between 15:1 and 20:1 — in line with the typical U.S. public-school staffing range.
Engagement
47.0%
chronically absent (missed 10%+ of school days)
Chronic absenteeism at or above 20% — the CDC threshold for "high" — signals significant barriers to regular attendance.
Funding equity
$21,992
per pupil, district-wide
— above California avg of $18,039
Above the U.S. public-school average, reflecting higher local or state investment per enrolled student.
Support staff
Counselors1.0 FTE
Per 251 students — the combined health-and-guidance staffing load for this school.
Discipline context
0
in-school suspensions + 1 out-of-school
Suspension rate: 0.0 per 100 students. Combined in-school and out-of-school rate: 0.4 per 100 students. Reported via the Civil Rights Data Collection.
Overview
Enrollment 251 Top 21% in California — larger than 79% of 10,006 state schools
Teachers (FTE) 14.0
Students per teacher 18.4:1 -15% vs state
Free-lunch eligible 49.4% -11% vs state
NCES ID 063132004836
Student demographics
Hispanic or Latino 59.8%
Asian 14.7%
White 10.0%
Two or More 9.2%
African American 6.4%
Largest group: Hispanic or Latino at 59.8% of enrollment.
Programs & staff
Gifted & talented Yes
Counselors (FTE) 1.0
Students per counselor 251:1
Discipline & special education
Chronically absent 47.0%
In-school suspensions 0
Out-of-school suspensions 1
Funding & spending
District-wide per-pupil expenditure for Pomona Unified, which includes Armstrong Elementary.
$21,992
Per student
+22%
vs California
Avg $18,039
+13%
vs U.S.
Avg $19,490
Revenue mix
Local 21.6%
State 60.9%
Federal 17.6%
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.
Other Schools in This District
- Enrollment
- 1,567
- Students per teacher
- 22.2:1
- Enrollment
- 1,542
- Students per teacher
- 23.4:1
- Enrollment
- 1,204
- Students per teacher
- 26.2:1
- Enrollment
- 993
- Students per teacher
- 19.6:1
- Enrollment
- 895
- Students per teacher
- 20.3:1
Similar elementary schools in Diamond Bar
6 comparable elementary schools (grades K-5) serving the same city.
Evergreen Elementary
Standard public school
709 students 25.7:1 students per teacher
Quail Summit Elementary
Standard public school
696 students 26.6:1 students per teacher
Castle Rock Elementary
Standard public school
684 students 24.8:1 students per teacher
Maple Hill Elementary
Standard public school
556 students 28.1:1 students per teacher
Pantera Elementary
Standard public school
512 students 22.2:1 students per teacher
Golden Springs Elementary
Standard public school
388 students 25.8:1 students per teacher
Educator & family resources
In-depth guides on understanding NCES data, school choice, and education funding.
Understanding NCES data
How CCD, CRDC and EDFacts feed every public-school number you see.
Choose a school district
Eight signals that matter more than the overall ranking number.
How schools are funded
Title I, F-33, state aid formulas and what per-pupil spending really means.
Chronic absenteeism
Why missing 10% of school matters and how it varies by district.
Magnet vs charter vs traditional
Three school types, three funding models, three sets of trade-offs.
School discipline data
What CRDC suspension and expulsion records do and don't reveal.
Frequently asked questions about Armstrong Elementary
How many students attend Armstrong Elementary?
Armstrong Elementary has 251 students enrolled. It is a elementary school in Diamond Bar, CA.
What is the student-teacher ratio at Armstrong Elementary?
The student-teacher ratio at Armstrong Elementary is 18.4:1, which is 15% lower than the California average of 21.6:1 and 16% higher than the national average of 15.9:1. Lower ratios generally mean more individual attention per student.
What percentage of students receive free lunch at Armstrong Elementary?
49.4% of students at Armstrong Elementary are eligible for free lunch, compared to the California average of 55.5%.
What is the racial and ethnic makeup of Armstrong Elementary?
The largest demographic group at Armstrong Elementary is Hispanic or Latino at 59.8%. The school serves a diverse student body in Diamond Bar, CA.
What is the Resource Investment Index for Armstrong Elementary?
Armstrong Elementary has a Resource Investment Index of 37/100 (F) based on 4 factors: student-teacher ratio, counselor availability, attendance rates. This index measures federal resource allocation — staffing levels, program availability, and support services — not standardized test scores or academic outcomes.