Enrollment
1,439
Washington · 2024-25 NCES data
High school (grades 9-12) · Mercer Island, WA
Mercer Island High School
Federal NCES profile for Mercer Island High School, including enrollment, faculty, free-lunch eligibility, demographics, and resource indicators - Resource Investment Index 62/100.
2024-25 NCES dataHigh school (grades 9-12)NCES 530498000761
👥 S:T ratio 22
📚 AP courses 100
🌟 Gifted program 70
🎓 Counselors 42
📋 Attendance 74
Scored 0–100 from federal NCES and CRDC indicators, resource allocation, not test scores. Full methodology →
The verdict
Mercer Island High School earns 62/100 on the Resource Investment Index, with class sizes larger than 75% of Washington schools. It is also one of the largest schools in Washington.
- #5 of 6
- public schools in Mercer Island · Resource Index
- 62
- Resource Index · Higher
- 19.4:1
- large classes for Washington
- 4.5%
- free-lunch eligible
Mercer Island High School has class sizes larger than 75% of Washington schools. Computed live against every Washington school reporting to NCES.
By Resource Investment Index, Mercer Island High School ranks #5 of 6 public schools in Mercer Island, WA.
School address
District: Mercer Island School District · Washington
NCES ID 530498000761 Verify on NCES CCD record →
Teachers (FTE)
74.0
Federal CCD staff survey
Students per teacher
19.4:1
vs 17.6:1 Washington avg
+10% vs state
Free-lunch eligible
4.5%
vs 45.0% Washington avg
-90% vs state
Student-teacher ratio in context
How Mercer Island High School compares with Washington and U.S. medians
What stands out at Mercer Island High School
Mercer Island High School is a lower-poverty, large high school in Mercer Island, Washington, enrolling 1,439 students.
Class loads run somewhat heavier than typical: 19.4:1 puts it in the larger third of Washington schools by student-teacher ratio.
Comparatively few students face economic hardship here, 4.5% free-meal eligibility runs 90% below the Washington average.
By headcount it is one of the larger campuses in Washington, bigger than 96% of state schools at 1,439 students.
Its Resource Investment Index lands in the upper third of 2,394 scored Washington schools.
Among 39 similarly sized, similarly resourced-need Washington schools statewide, it ranks #3, a top-tier result once campus size and economic need are matched.
Its student body is led by White (52%) and Asian (25%) (diversity index 64/100).
On the academic-pipeline side it reports 29 Advanced Placement courses.
Counselor coverage runs a bit thin, about 293 students per counselor, somewhat past the ASCA-recommended 250:1 benchmark.
10.4% of students were chronically absent in the 2021-22 collection, in line with the post-pandemic national range.
Mercer Island School District also operates Islander Middle School (960 students) and West Mercer Elementary (431 students) alongside Mercer Island High School.
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 Mercer Island High School compares
Mercer Island High School on the metrics families compare, against Washington and U.S. means.
| Metric | This school | vs Washington | Washington avg | U.S. avg |
|---|---|---|---|---|
| Students per teacher | 19.4:1 | ▲ 10% | 17.6:1 | 15.7:1 |
| Free-lunch eligible | 4.5% | ▼ 90% | 45.0% | 51.7% |
| Enrollment | 1,439 | top 4% | - | - |
Source: NCES Common Core of Data School-level CCD + state/national means from Public School Universe · 2024-25
19.4:1
Leaner classes than 18% of US schools, heavier class loads than most.
1,439
Bigger than 96% of US schools by enrollment, a large campus nationally.
Equity indicators (what these measure)
Economic need
4.5%
free-lunch eligible
- 90% below the Washington average of 45.0%
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
19.4:1
students per teacher
- 10% above state mean
Top 75% in Washington - lower ratio than 25% of state schools
Between 16:1 and 20:1, squarely in the typical U.S. public-school staffing range.
Engagement
10.4%
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
$17,431
per pupil, district-wide
- below Washington avg of $19,487
Somewhat above the U.S. public-school average, reflecting higher local or state investment per enrolled student.
Support staff
Counselors4.9 FTE
Per 292 students, the combined health-and-guidance staffing load for this school.
Discipline context
4
in-school suspensions + 6 out-of-school
Suspension rate: 0.3 per 100 students. Combined in-school and out-of-school rate: 0.7 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
White 52.1%
Asian 25.4%
Two or More 13.5%
Hispanic or Latino 7.2%
African American 1.4%
Native Hawaiian / Pacific Islander 0.4%
American Indian / Alaska Native 0.1%
Largest group: White at 52.1% of enrollment.
Student-body diversity index 64.0/100
Simpson diversity index - at 64.0, Mercer Island High School is more mixed than the Washington school average of 53.3.
Programs
AP courses offered 29
Gifted & talented Yes
Funding & spending
District-wide per-pupil expenditure for Mercer Island School District, which includes Mercer Island High School.
$17,431
Per student
-11%
vs Washington
Avg $19,487
+5%
vs U.S.
Avg $16,593
Revenue mix
Local 37.6%
State 56.3%
Federal 6.2%
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 Mercer Island High School Compares to District-Mates
| School | Enrollment | Economic Profile | Student-Teacher Ratio |
|---|---|---|---|
| Islander Middle School | Smaller | Similar economic need | Higher S:T ratio |
| West Mercer Elementary | Smaller | Similar economic need | Similar S:T ratio |
| Lakeridge Elementary School | Smaller | Similar economic need | Similar S:T ratio |
| Northwood Elementary School | Smaller | Similar economic need | Lower S:T ratio |
| Island Park Elementary | Smaller | Similar economic need | Lower S:T ratio |
Comparisons are relative to Mercer Island High School's own figures; each column derives from NCES Common Core of Data.
Other Schools in This District
- Enrollment
- 960
- Students per teacher
- 20.9:1
- Resource Index
- 51/100
- Enrollment
- 431
- Students per teacher
- 18.7:1
- Resource Index
- 62/100
- Enrollment
- 401
- Students per teacher
- 19.1:1
- Resource Index
- 62/100
- Enrollment
- 398
- Students per teacher
- 15.3:1
- Resource Index
- 66/100
- Enrollment
- 364
- Students per teacher
- 15.8:1
- Resource Index
- 65/100
Similar high schools statewide
Matched by enrollment size and by staffing ratio across all of Washington, not just this city - a different peer set than the local comparisons above.
Similar enrollment (~1,439 students)
Similar student-teacher ratio (~19.4:1)
Next steps
Verify locally before acting on Mercer Island High School's federal record.
- Compare Mercer Island High School against another school. Compare schools
- Mercer Island School District'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 Mercer Island High School
How many students attend Mercer Island High School?
Mercer Island High School has 1,439 students enrolled. It is a high school in Mercer Island, WA.
What is the student-teacher ratio at Mercer Island High School?
The student-teacher ratio at Mercer Island High School is 19.4:1, which is 10% higher than the Washington average of 17.6:1 and 24% higher than the national average of 15.7:1.
What percentage of students receive free lunch at Mercer Island High School?
4.5% of students at Mercer Island High School are eligible for free lunch, compared to the Washington average of 45.0%.
What is the racial and ethnic makeup of Mercer Island High School?
The largest demographic group at Mercer Island High School is White at 52.1% of enrollment, in Mercer Island, WA. Its student body is more racially and ethnically mixed than most US schools, with a diversity index of 64.0/100.
What is the Resource Investment Index for Mercer Island High School?
Mercer Island High School has a Resource Investment Index of 62/100 (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 Mercer Island High School rank among public schools in Mercer Island?
By Resource Investment Index, Mercer Island High School ranks #5 of 6 public schools in Mercer Island, WA. This compares federal resource and staffing data among local peers; it is not a test-score or academic ranking. See all public schools in Mercer Island on the city page.
Is Mercer Island High School a good school?
Mercer Island High School earns 62/100 on the Resource Investment Index, with class sizes larger than 75% of Washington schools. It is also one of the largest schools in Washington. 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 Mercer Island School District?
Besides Mercer Island High School, Mercer Island School District also operates Islander Middle School (960 students), West Mercer Elementary (431 students), and Lakeridge Elementary School (401 students). See the Mercer Island School District 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.