- Enrollment
- 1,443
- Students per teacher
- 16.6:1
- Resource Index
- 34/100
High school (grades 9-12) · Crystal Lake, IL
Crystal Lake South High School
Federal NCES profile for Crystal Lake South High School, including enrollment, faculty, free-lunch eligibility, demographics, and resource indicators - Resource Investment Index 39/100.
2024-25 NCES dataHigh school (grades 9-12)NCES 171137001368
👥 S:T ratio 30
🌟 Gifted program 30
🎓 Counselors 49
📋 Attendance 47
Scored 0–100 from federal NCES and CRDC indicators, resource allocation, not test scores. Full methodology →
The verdict
Crystal Lake South High School earns 39/100 on the Resource Investment Index, with class sizes larger than 89% of Illinois schools. It is also one of the largest schools in Illinois.
- #2 of 3
- high schools in Crystal Lake · Resource Index
- 39
- Resource Index · Typical
- 17.5:1
- large classes for Illinois
- 1,279
- students enrolled
Crystal Lake South High School has class sizes larger than 89% of Illinois schools. Computed live against every Illinois school reporting to NCES.
By Resource Investment Index, Crystal Lake South High School ranks #2 of 3 high schools in Crystal Lake, IL.
School address
NCES ID 171137001368 Verify on NCES CCD record →
CCD year-over-year · 2022-23 → 2023-24
-10 students YoY
Crystal Lake South High School held near 1,291 students from 2022-23 to 2023-24 (-10 headcount).
Teacher FTE added 74.0 → 74.9 across the same CCD years.
Source: NCES Common Core of Data public-school universe (2022-23, 2023-24).
Steady CCD campus
-10 students YoY 171137001368 · Crystal Lake, IL High · MID · TRAD
1,279 enr · 17.5:1 · RII 39
Nearest enrollment peer: Crystal Lake Central High School (1,443 students)
Crystal Lake South High School held near 1,291 students from 2022-23 to 2023-24 (-10 headcount). Teacher FTE added 74.0 → 74.9 across the same CCD years. Read with this school → · District book → · Illinois schools → · Find another →
Crystal Lake South High School in the enrollment neighbourhood
Fall enrollment among this campus and nearest district peers
- Crystal Lake C
Crystal Lake Central High School
1,443 students
- Cary-Grove Com
Cary-Grove Community High School
1,348 students
- This school
Crystal Lake South High School
1,279 students
- Prairie Ridge
Prairie Ridge High School
1,133 students
What this shows Crystal Lake South High School reports 1,279 students on the CCD universe file.
How Crystal Lake South High School compares
Crystal Lake South High School held steady on CCD headcount: ratios and free-lunch share vs Illinois and U.S. means.
| Metric | This school | vs Illinois | Illinois avg | U.S. avg |
|---|---|---|---|---|
| Students per teacher | 17.5:1 | ▲ 25% | 14:1 | 15.7:1 |
| Enrollment | 1,279 | top 5% | - | - |
Source: NCES Common Core of Data School-level CCD + state/national means from Public School Universe · 2024-25
17.5:1
Leaner classes than 27% of US schools, heavier class loads than most.
1,279
Bigger than 95% of US schools by enrollment, a large campus nationally.
Equity indicators methodology
Staffing depth
17.5:1
students per teacher
- 25% above state mean
Top 89% in Illinois - lower ratio than 11% of state schools
Between 16:1 and 20:1, squarely in the typical U.S. public-school staffing range.
Engagement
21.3%
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
$23,700
per pupil, district-wide
- above Illinois avg of $18,196
Well above the U.S. public-school average, reflecting substantially higher local or state investment per enrolled student.
Support staff
Counselors5.0 FTE
Per 256 students, the combined health-and-guidance staffing load for this school.
Discipline context
122
in-school suspensions + 56 out-of-school
Suspension rate: 9.5 per 100 students. Combined in-school and out-of-school rate: 13.9 per 100 students. Reported via the Civil Rights Data Collection.
Student demographics
White 64.9%
Hispanic or Latino 25.7%
Asian 4.3%
African American 2.7%
Two or More 2.0%
American Indian / Alaska Native 0.3%
Largest group: White at 64.9% of enrollment.
Student-body diversity index 51.0/100
Simpson diversity index - at 51.0, Crystal Lake South High School is more mixed than the Illinois school average of 38.9.
Programs
AP courses offered 20
District finance for Chsd 155 reports $23,700 per pupil (NCES F-33) - open the district page for the full revenue mix.
How Crystal Lake South High School Compares to District-Mates
| School | Enrollment | Economic Profile | Student-Teacher Ratio |
|---|---|---|---|
| Crystal Lake Central High School | Similar size | No free-lunch data | Similar S:T ratio |
| Cary-Grove Community High School | Similar size | No free-lunch data | Similar S:T ratio |
| Prairie Ridge High School | Similar size | No free-lunch data | Lower S:T ratio |
Comparisons are relative to Crystal Lake South High School's own figures; each column derives from NCES Common Core of Data.
Other Schools in This District
- Enrollment
- 1,348
- Students per teacher
- 16.2:1
- Resource Index
- 41/100
- Enrollment
- 1,133
- Students per teacher
- 16:1
- Resource Index
- 42/100
Similar high schools in Crystal Lake
2 comparable high schools (grades 9-12) serving the same city.
Nationwide high 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 (~1,279 students)
Frequently asked questions about Crystal Lake South High School
How many students attend Crystal Lake South High School?
Crystal Lake South High School has 1,279 students enrolled. It is a high school in Crystal Lake, IL. CCD year-over-year: 1,301 (2022-23) → 1,291 (2023-24), nearly flat (-10).
What is the student-teacher ratio at Crystal Lake South High School?
The student-teacher ratio at Crystal Lake South High School is 17.5:1, which is 25% higher than the Illinois average of 14:1 and 11% higher than the national average of 15.7:1.
What is the racial and ethnic makeup of Crystal Lake South High School?
The largest demographic group at Crystal Lake South High School is White at 64.9% of enrollment, in Crystal Lake, IL. Its student body is more racially and ethnically mixed than most US schools, with a diversity index of 51.0/100.
What is the Resource Investment Index for Crystal Lake South High School?
Crystal Lake South High School has a Resource Investment Index of 39/100 (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 Crystal Lake South High School rank among high schools in Crystal Lake?
By Resource Investment Index, Crystal Lake South High School ranks #2 of 3 high schools in Crystal Lake, IL. This compares federal resource and staffing data among local peers; it is not a test-score or academic ranking. See all high schools in Crystal Lake on the city page.
What other schools are in Chsd 155?
Besides Crystal Lake South High School, Chsd 155 also operates Crystal Lake Central High School (1,443 students), Cary-Grove Community High School (1,348 students), and Prairie Ridge High School (1,133 students). See the Chsd 155 district page for the complete list.