Enrollment
172
Illinois · 2024-25 NCES data
High school (grades 9-12) · Mason City, IL
Illini Central High School
Federal NCES profile for Illini Central High School, including enrollment, faculty, free-lunch eligibility, demographics, and resource indicators - Resource Investment Index 35/100.
2024-25 NCES dataHigh school (grades 9-12)NCES 170011305387
👥 S:T ratio 64
📚 AP courses 5
🌟 Gifted program 30
🎓 Counselors 66
📋 Attendance 8
Scored 0–100 from federal NCES and CRDC indicators, resource allocation, not test scores. Full methodology →
The verdict
Illini Central High School earns 35/100 on the Resource Investment Index, with class sizes smaller than 94% of Illinois schools. It is also less racially and ethnically mixed than most Illinois schools.
- #3 of 4
- public schools in Mason City · Resource Index
- 35
- Resource Index · Typical
- 9.1:1
- small classes for Illinois
- 172
- students enrolled
Illini Central High School has class sizes smaller than 94% of Illinois schools. Computed live against every Illinois school reporting to NCES.
By Resource Investment Index, Illini Central High School ranks #3 of 4 public schools in Mason City, IL.
School address
District: Illini Central Cusd 189 · Illinois
NCES ID 170011305387 Verify on NCES CCD record →
Teachers (FTE)
19.0
Federal CCD staff survey
Students per teacher
9.1:1
vs 14:1 Illinois avg
-35% vs state
Student-teacher ratio in context
How Illini Central High School compares with Illinois and U.S. medians
What stands out at Illini Central High School
Illini Central High School is a small high school in Mason City, Illinois, enrolling 172 students.
Classes run notably small here: at 9.1:1, Illini Central High School is leaner than roughly 94% of Illinois schools and 35% under the state's 14:1 norm, more adult attention per pupil than most peers.
Enrollment of 172 puts it in the smaller third of Illinois schools by headcount.
Its Resource Investment Index sits near the middle of the pack among 3,845 scored Illinois schools.
Its student body is predominantly White (96% of enrollment), among the less diverse in the state (diversity index 8/100).
On the academic-pipeline side it reports 1 Advanced Placement course.
Counselor coverage is strong, about 172 students per counselor, inside the American School Counselor Association's recommended 250:1.
Chronic absenteeism is elevated: 36.6% of students missed 10% or more of school days (2021-22 Civil Rights Data Collection).
Illini Central Cusd 189 also operates Illini Central Grade School (264 students) and Illini Central Middle School (139 students) alongside Illini Central 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 Illini Central High School compares
Illini Central High School on the metrics families compare, against Illinois and U.S. means.
| Metric | This school | vs Illinois | Illinois avg | U.S. avg |
|---|---|---|---|---|
| Students per teacher | 9.1:1 | ▼ 35% | 14:1 | 15.7:1 |
| Enrollment | 172 | top 86% | - | - |
Source: NCES Common Core of Data School-level CCD + state/national means from Public School Universe · 2024-25
9.1:1
Leaner classes than 92% of US schools, among the more generously staffed nationally.
172
Bigger than 17% of US schools by enrollment, a small campus.
Equity indicators (what these measure)
Staffing depth
9.1:1
students per teacher
- 35% below state mean
Top 6% in Illinois - lower ratio than 94% of state schools
Well under the widely cited 15:1 individualized-attention benchmark, among the leaner class loads nationally.
Engagement
36.6%
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
$15,441
per pupil, district-wide
- below Illinois avg of $17,042
Somewhat below the U.S. average per-pupil spend; funding constraints may affect programs, facilities, and staffing.
Support staff
Counselors1.0 FTE
Per 172 students, the combined health-and-guidance staffing load for this school.
Discipline context
0
in-school suspensions + 25 out-of-school
Suspension rate: 0.0 per 100 students. Combined in-school and out-of-school rate: 14.5 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 95.9%
Two or More 2.3%
Hispanic or Latino 1.7%
Largest group: White at 95.9% of enrollment.
Student-body diversity index 8.0/100
Simpson diversity index - at 8.0, Illini Central High School is less mixed than the Illinois school average of 38.9.
Programs
AP courses offered 1
Funding & spending
District-wide per-pupil expenditure for Illini Central Cusd 189, which includes Illini Central High School.
$15,441
Per student
-9%
vs Illinois
Avg $17,042
-7%
vs U.S.
Avg $16,593
Revenue mix
Local 52.4%
State 36.2%
Federal 11.5%
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 Illini Central High School Compares to District-Mates
| School | Enrollment | Economic Profile | Student-Teacher Ratio |
|---|---|---|---|
| Illini Central Grade School | Larger | No free-lunch data | Similar S:T ratio |
| Illini Central Middle School | Similar size | No free-lunch data | Higher S:T ratio |
| West Campus Facility | Smaller | No free-lunch data | Higher S:T ratio |
Comparisons are relative to Illini Central High School's own figures; each column derives from NCES Common Core of Data.
Other Schools in This District
- Enrollment
- 264
- Students per teacher
- 9.8:1
- Resource Index
- 41/100
- Enrollment
- 139
- Students per teacher
- 11.6:1
- Resource Index
- 43/100
- Enrollment
- 65
- Students per teacher
- 21.7:1
- Resource Index
- 43/100
Similar high schools statewide
Matched by enrollment size and by staffing ratio across all of Illinois, not just this city - a different peer set than the local comparisons above.
Similar enrollment (~172 students)
Similar student-teacher ratio (~9.1:1)
Next steps
Verify locally before acting on Illini Central High School's federal record.
- Compare Illini Central High School against another school. Compare schools
- Illini Central Cusd 189'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 Illini Central High School
How many students attend Illini Central High School?
Illini Central High School has 172 students enrolled. It is a high school in Mason City, IL.
What is the student-teacher ratio at Illini Central High School?
The student-teacher ratio at Illini Central High School is 9.1:1, which is 35% lower than the Illinois average of 14:1 and 42% lower than the national average of 15.7:1. Lower ratios generally mean more individual attention per student.
What is the racial and ethnic makeup of Illini Central High School?
The largest demographic group at Illini Central High School is White at 95.9% of enrollment, in Mason City, IL.
What is the Resource Investment Index for Illini Central High School?
Illini Central High School has a Resource Investment Index of 35/100 (typical 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 Illini Central High School rank among public schools in Mason City?
By Resource Investment Index, Illini Central High School ranks #3 of 4 public schools in Mason City, IL. This compares federal resource and staffing data among local peers; it is not a test-score or academic ranking. See all public schools in Mason City on the city page.
Is Illini Central High School a good school?
Illini Central High School earns 35/100 on the Resource Investment Index, with class sizes smaller than 94% of Illinois schools. It is also less racially and ethnically mixed than most Illinois 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 Illini Central Cusd 189?
Besides Illini Central High School, Illini Central Cusd 189 also operates Illini Central Grade School (264 students), Illini Central Middle School (139 students), and West Campus Facility (65 students). See the Illini Central Cusd 189 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.