Enrollment
1,115
California · 2024-25 NCES data
High school (grades 9-12) · Millbrae, CA
Mills High
Federal NCES profile for Mills High, including enrollment, faculty, free-lunch eligibility, demographics, and resource indicators - Resource Investment Index 49/100.
2024-25 NCES dataHigh school (grades 9-12)NCES 063498005924
👥 S:T ratio 16
📚 AP courses 90
🌟 Gifted program 30
🎓 Counselors 38
📋 Attendance 69
Scored 0–100 from federal NCES and CRDC indicators, resource allocation, not test scores. Full methodology →
The verdict
Mills High earns 49/100 on the Resource Investment Index, with class sizes near the California median.
- #1 of 5
- public schools in Millbrae · Resource Index
- 49
- Resource Index · Higher
- 21:1
- students per teacher
- 17.0%
- free-lunch eligible
Mills High has class sizes near the California median. Computed live against every California school reporting to NCES.
By Resource Investment Index, Mills High ranks #1 of 5 public schools in Millbrae, CA.
School address
District: San Mateo Union High · California
NCES ID 063498005924 Verify on NCES CCD record →
Teachers (FTE)
53.0
Federal CCD staff survey
Students per teacher
21:1
vs 21.5:1 California avg
-2% vs state
Free-lunch eligible
17.0%
vs 55.5% California avg
-69% vs state
Student-teacher ratio in context
How Mills High compares with California and U.S. medians
What stands out at Mills High
Mills High is a lower-poverty, large high school in Millbrae, California, enrolling 1,115 students.
At 21:1, its student-teacher ratio sits close to the California median, within a few percentage points of the 21.5:1 state norm, neither notably crowded nor notably small.
Comparatively few students face economic hardship here, 17.0% free-meal eligibility runs 69% below the California average.
By headcount it is one of the larger campuses in California, bigger than 91% of state schools at 1,115 students.
Its Resource Investment Index lands in the upper third of 9,998 scored California schools.
Against 541 statewide peers matched on enrollment and economic need, it ranks in the upper tier at #199.
Its student body is led by Asian (59%) and Hispanic or Latino (20%) (diversity index 59/100).
On the academic-pipeline side it reports 18 Advanced Placement courses.
Counselor coverage runs a bit thin, about 310 students per counselor, somewhat past the ASCA-recommended 250:1 benchmark.
12.6% of students were chronically absent in the 2021-22 collection, in line with the post-pandemic national range.
The surrounding San Mateo Union High spends $22,262 per pupil, 35% above the California average, a better-resourced district than most.
The federal civil-rights collection also records 1 expulsion at this campus for 2021-22.
San Mateo Union High also operates Aragon High (1,658 students) and Hillsdale High (1,585 students) alongside Mills High.
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 Mills High compares
Mills High on the metrics families compare, against California and U.S. means.
| Metric | This school | vs California | California avg | U.S. avg |
|---|---|---|---|---|
| Students per teacher | 21:1 | ▼ 2% | 21.5:1 | 15.7:1 |
| Free-lunch eligible | 17.0% | ▼ 69% | 55.5% | 51.7% |
| Enrollment | 1,115 | top 9% | - | - |
Source: NCES Common Core of Data School-level CCD + state/national means from Public School Universe · 2024-25
21:1
Leaner classes than 13% of US schools, heavier class loads than most.
1,115
Bigger than 93% of US schools by enrollment, a large campus nationally.
Equity indicators (what these measure)
Economic need
17.0%
free-lunch eligible
- 69% below the California average of 55.5%
Below the 40% Title I threshold, among the lower-need profiles in the state; federal aid targets individual qualifying students rather than schoolwide programs.
Staffing depth
21:1
students per teacher
- 2% below state mean
Top 43% in California - lower ratio than 57% of state schools
Above 20:1, running heavier than the typical U.S. public school; staffing is comparatively stretched.
Engagement
12.6%
chronically absent (missed 10%+ of school days)
In the 10-15% range, above the pre-pandemic national baseline but within the broader post-pandemic picture.
Funding equity
$22,262
per pupil, district-wide
- above California avg of $16,509
Well above the U.S. public-school average, reflecting substantially higher local or state investment per enrolled student.
Support staff
Counselors3.6 FTE
Per 310 students, the combined health-and-guidance staffing load for this school.
Discipline context
7
in-school suspensions + 26 out-of-school
Suspension rate: 0.6 per 100 students. Combined in-school and out-of-school rate: 3.0 per 100 students. Reported via the Civil Rights Data Collection. Includes 1 expulsion.
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
Asian 58.8%
Hispanic or Latino 20.3%
White 10.7%
Two or More 9.0%
Native Hawaiian / Pacific Islander 1.0%
African American 0.3%
Largest group: Asian at 58.8% of enrollment.
Student-body diversity index 59.3/100
Simpson diversity index - at 59.3, Mills High is more mixed than the California school average of 46.0.
Programs
AP courses offered 18
Funding & spending
District-wide per-pupil expenditure for San Mateo Union High, which includes Mills High.
$22,262
Per student
+35%
vs California
Avg $16,509
+34%
vs U.S.
Avg $16,593
Revenue mix
Local 85.1%
State 11.5%
Federal 3.4%
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 Mills High Compares to District-Mates
| School | Enrollment | Economic Profile | Student-Teacher Ratio |
|---|---|---|---|
| Aragon High | Larger | Similar economic need | Similar S:T ratio |
| Hillsdale High | Larger | Similar economic need | Lower S:T ratio |
| Burlingame High | Larger | Similar economic need | Similar S:T ratio |
| San Mateo High | Larger | Similar economic need | Lower S:T ratio |
| Capuchino High | Similar size | Similar economic need | Lower S:T ratio |
Comparisons are relative to Mills High's own figures; each column derives from NCES Common Core of Data.
Other Schools in This District
- Enrollment
- 1,658
- Students per teacher
- 22.1:1
- Resource Index
- 33/100
- Enrollment
- 1,585
- Students per teacher
- 17.2:1
- Resource Index
- 38/100
- Enrollment
- 1,583
- Students per teacher
- 22:1
- Resource Index
- 36/100
- Enrollment
- 1,557
- Students per teacher
- 18.5:1
- Resource Index
- 30/100
- Enrollment
- 1,061
- Students per teacher
- 17.4:1
- Resource Index
- 33/100
Similar high schools statewide
Matched by enrollment size and by staffing ratio across all of California, not just this city - a different peer set than the local comparisons above.
Similar enrollment (~1,115 students)
Similar student-teacher ratio (~21:1)
Next steps
Verify locally before acting on Mills High's federal record.
- Compare Mills High against another school. Compare schools
- San Mateo Union High'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 Mills High
How many students attend Mills High?
Mills High has 1,115 students enrolled. It is a high school in Millbrae, CA.
What is the student-teacher ratio at Mills High?
The student-teacher ratio at Mills High is 21:1, which is 2% lower than the California average of 21.5:1 and 34% 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 Mills High?
17.0% of students at Mills High are eligible for free lunch, compared to the California average of 55.5%.
What is the racial and ethnic makeup of Mills High?
The largest demographic group at Mills High is Asian at 58.8% of enrollment, in Millbrae, CA. Its student body is more racially and ethnically mixed than most US schools, with a diversity index of 59.3/100.
What is the Resource Investment Index for Mills High?
Mills High has a Resource Investment Index of 49/100 (higher reported resources relative to schools nationally) based on 5 factors: student-teacher ratio, AP course offerings, counselor availability, attendance rates. Not a test-score or academic measure (national median ~41/100, see methodology).
How does Mills High rank among public schools in Millbrae?
By Resource Investment Index, Mills High ranks #1 of 5 public schools in Millbrae, CA. This compares federal resource and staffing data among local peers; it is not a test-score or academic ranking. See all public schools in Millbrae on the city page.
Is Mills High a good school?
Mills High earns 49/100 on the Resource Investment Index, with class sizes near the California median. 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 San Mateo Union High?
Besides Mills High, San Mateo Union High also operates Aragon High (1,658 students), Hillsdale High (1,585 students), and Burlingame High (1,583 students). See the San Mateo Union High 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.