- Enrollment
- 1,567
- Students per teacher
- 20.9:1
- Resource Index
- 34/100
Elementary school (grades K-5) · Diamond Bar, CA
Armstrong Elementary
Federal NCES profile for Armstrong Elementary, including enrollment, faculty, free-lunch eligibility, demographics, and resource indicators - Resource Investment Index 37/100.
2024-25 NCES dataElementary school (grades K-5)NCES 063132004836
👥 S:T ratio 28
🌟 Gifted program 70
🎓 Counselors 50
📋 Attendance 0
Scored 0–100 from federal NCES and CRDC indicators, resource allocation, not test scores. Full methodology →
The verdict
Armstrong Elementary earns 37/100 on the Resource Investment Index, with class sizes smaller than 79% of California schools.
- #2 of 7
- elementary schools in Diamond Bar · Resource Index
- 37
- Resource Index · Typical
- 17.9:1
- small classes for California
- 49.4%
- free-lunch eligible
Armstrong Elementary has class sizes smaller than 79% of California schools. Computed live against every California school reporting to NCES.
By Resource Investment Index, Armstrong Elementary ranks #2 of 7 elementary schools in Diamond Bar, CA.
School address
District: Pomona Unified · California
NCES ID 063132004836 Verify on NCES CCD record →
CCD year-over-year · 2022-23 → 2023-24
-8 students YoY
Armstrong Elementary held near 249 students from 2022-23 to 2023-24 (-8 headcount).
Teacher FTE lost 14.0 → 12.0 across the same CCD years.
Source: NCES Common Core of Data public-school universe (2022-23, 2023-24).
Steady CCD campus
-8 students YoY 063132004836 · Diamond Bar, CA Elementary · SMALL · TRAD
251 enr · 17.9:1 · 49.4% lunch · RII 37
Nearest enrollment peer: Garey High (1,567 students)
Armstrong Elementary held near 249 students from 2022-23 to 2023-24 (-8 headcount). Teacher FTE lost 14.0 → 12.0 across the same CCD years. Read with this school → · District book → · California schools → · Find another →
Armstrong Elementary in the enrollment neighbourhood
Fall enrollment among this campus and nearest district peers
- Garey High
Garey High
1,567 students
- Diamond Ranch
Diamond Ranch High
1,542 students
- School of Exte
School of Extended Educational Options
1,204 students
- Pomona High
Pomona High
993 students
- Ganesha High
Ganesha High
895 students
- This school 251
Armstrong Elementary
251 students
What this shows Armstrong Elementary reports 251 students on the CCD universe file.
How Armstrong Elementary compares
Armstrong Elementary held steady on CCD headcount: ratios and free-lunch share vs California and U.S. means.
| Metric | This school | vs California | California avg | U.S. avg |
|---|---|---|---|---|
| Students per teacher | 17.9:1 | ▼ 17% | 21.5:1 | 15.7:1 |
| Free-lunch eligible | 49.4% | ▼ 11% | 55.5% | 51.7% |
| Enrollment | 251 | top 79% | - | - |
Source: NCES Common Core of Data School-level CCD + state/national means from Public School Universe · 2024-25
17.9:1
Leaner classes than 25% of US schools, heavier class loads than most.
251
Bigger than 25% of US schools by enrollment, mid-sized for the country.
Equity indicators methodology
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
17.9:1
students per teacher
- 17% below state mean
Top 21% in California - lower ratio than 79% of state schools
Between 16:1 and 20:1, squarely in the typical U.S. public-school staffing range.
Engagement
47.0%
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
$20,239
per pupil, district-wide
- above California avg of $18,665
Somewhat 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.
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.
Student-body diversity index 59.8/100
Simpson diversity index - at 59.8, Armstrong Elementary is more mixed than the California school average of 46.0.
Programs
Gifted & talented Yes
District finance for Pomona Unified reports $20,239 per pupil (NCES F-33) - open the district page for the full revenue mix.
How Armstrong Elementary Compares to District-Mates
| School | Enrollment | Economic Profile | Student-Teacher Ratio |
|---|---|---|---|
| Garey High | Larger | Higher economic need | Higher S:T ratio |
| Diamond Ranch High | Larger | Similar economic need | Higher S:T ratio |
| School of Extended Educational Options | Larger | Similar economic need | Higher S:T ratio |
| Pomona High | Larger | Higher economic need | Similar S:T ratio |
| Ganesha High | Larger | Higher economic need | Higher S:T ratio |
Comparisons are relative to Armstrong Elementary's own figures; each column derives from NCES Common Core of Data.
Other Schools in This District
- Enrollment
- 1,542
- Students per teacher
- 23.4:1
- Resource Index
- 36/100
- Enrollment
- 1,204
- Students per teacher
- 32.5:1
- Resource Index
- 43/100
- Enrollment
- 993
- Students per teacher
- 16.6:1
- Resource Index
- 37/100
- Enrollment
- 895
- Students per teacher
- 19.5:1
- Resource Index
- 35/100
Similar elementary schools in Diamond Bar
6 comparable elementary schools (grades K-5) serving the same city.
Evergreen Elementary
Standard public school
709 students 25.3:1 students per teacher
Quail Summit Elementary
Standard public school
696 students 27.8:1 students per teacher
Castle Rock Elementary
Standard public school
684 students 26.3:1 students per teacher
Maple Hill Elementary
Standard public school
556 students 27.8:1 students per teacher
Pantera Elementary
Standard public school
512 students 24.4:1 students per teacher
Golden Springs Elementary
Standard public school
388 students 24.3:1 students per teacher
Nationwide elementary 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 (~251 students)
Frequently asked questions about Armstrong Elementary
How many students attend Armstrong Elementary?
Armstrong Elementary has 251 students enrolled. It is an elementary school in Diamond Bar, CA. CCD year-over-year: 257 (2022-23) → 249 (2023-24), nearly flat (-8).
What is the student-teacher ratio at Armstrong Elementary?
The student-teacher ratio at Armstrong Elementary is 17.9:1, which is 17% lower than the California average of 21.5:1 and 14% higher than the national average of 15.7:1. 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% of enrollment, in Diamond Bar, CA. Its student body is more racially and ethnically mixed than most US schools, with a diversity index of 59.8/100.
What is the Resource Investment Index for Armstrong Elementary?
Armstrong Elementary has a Resource Investment Index of 37/100 (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 Armstrong Elementary rank among elementary schools in Diamond Bar?
By Resource Investment Index, Armstrong Elementary ranks #2 of 7 elementary schools in Diamond Bar, CA. This compares federal resource and staffing data among local peers; it is not a test-score or academic ranking. See all elementary schools in Diamond Bar on the city page.
What other schools are in Pomona Unified?
Besides Armstrong Elementary, Pomona Unified also operates Garey High (1,567 students), Diamond Ranch High (1,542 students), and School of Extended Educational Options (1,204 students). See the Pomona Unified district page for the complete list.