Enrollment
1,279
Illinois · 2024-25 NCES data
2024-25 NCES data High school (grades 9-12) NCES 171137001368
Crystal Lake South High School — Crystal Lake, IL
Federal NCES profile for Crystal Lake South High School, including enrollment, faculty, free-lunch eligibility, demographics, and resource indicators — composite Resource Quality Score 51/100.
School address
Public location data per NCES (National Center for Education Statistics) Common Core of Data. Verify the school's current address on the NCES CCD record.
Teachers (FTE)
73.0
Federal CCD staff survey
Students per teacher
17.8:1
vs 14.6:1 Illinois avg
+22% vs state
Student-teacher ratio in context
How Crystal Lake South High School compares with Illinois and U.S. medians
What this school's NCES data tells you
Crystal Lake South High School reports 1,279 enrolled students to the National Center for Education Statistics (NCES) alongside 73.0 full-time-equivalent teachers, producing a 17.8:1 student-teacher ratio. That figure sits 22% above the Illinois state mean of 14.6:1, signalling larger average class loads than peers in the same state. Against the national 2024-25 average of 15.9:1, it is 12% higher, a useful calibration for families comparing districts across state lines.
The school offers 20 Advanced Placement courses, a stronger academic pipeline indicator than enrollment alone. Counselor coverage works out to roughly 256 students per counselor, above the ASCA-recommended ceiling of 250:1. Chronic absenteeism — missing 10% or more of school days — stands at 21.3% according to the 2021-22 Civil Rights Data Collection.
On the finance side, the surrounding Chsd 155 spends $23,625 per pupil district-wide, above the Illinois average of $20,099 and above the national average of $19,490. Revenue comes 62.5% from local sources (property taxes), 31.9% from the state, and 5.6% from federal programs per the NCES F-33 finance survey. Taken together, these measurements produce a composite Resource Quality Grade of C- (51/100), calculated from 5 distinct NCES and CRDC indicators.
Source: National Center for Education Statistics Common Core of Data + CRDC + F-33 · 2024-25
How Crystal Lake South High School compares
Cross-validating school-level NCES values against Illinois state and U.S. national means lets readers see whether this school is an outlier or in line with peers.
| Metric | This school | Illinois avg | U.S. avg |
|---|---|---|---|
| Students per teacher | 17.8:1 | 14.6:1 | 15.9:1 |
| Enrollment (students) | 1,279 | — | — |
Source: NCES Common Core of Data School-level CCD + state/national means from Public School Universe · 2024-25
Overview
Enrollment 1,279
Teachers (FTE) 73.0
Students per teacher 17.8:1 +22% vs state
Free-lunch eligible —
NCES ID 171137001368
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.
Programs & staff
AP courses offered 20
Counselors (FTE) 5.0
Students per counselor 256:1
Discipline & special education
Chronically absent 21.3%
In-school suspensions 122
Out-of-school suspensions 56
Funding & spending
District-wide per-pupil expenditure for Chsd 155, which includes Crystal Lake South High School.
$23,625
Per student
+18%
vs Illinois
Avg $20,099
+21%
vs U.S.
Avg $19,490
Revenue mix
Local 62.5%
State 31.9%
Federal 5.6%
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.
Other Schools in This District
- Enrollment
- 1,443
- Students per teacher
- 16.9:1
- Enrollment
- 1,348
- Students per teacher
- 18:1
- Enrollment
- 1,133
- Students per teacher
- 16.1:1
Similar high schools in Crystal Lake
2 comparable high schools (grades 9-12) serving the same city.
Educator & family resources
In-depth guides on understanding NCES data, school choice, and education funding.
Understanding NCES data
How CCD, CRDC and EDFacts feed every public-school number you see.
Choose a school district
Eight signals that matter more than the overall ranking number.
How schools are funded
Title I, F-33, state aid formulas and what per-pupil spending really means.
Chronic absenteeism
Why missing 10% of school matters and how it varies by district.
Magnet vs charter vs traditional
Three school types, three funding models, three sets of trade-offs.
School discipline data
What CRDC suspension and expulsion records do and don't reveal.
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.
What is the student-teacher ratio at Crystal Lake South High School?
The student-teacher ratio at Crystal Lake South High School is 17.8:1, which is 22% higher than the Illinois average of 14.6:1 and 12% higher than the national average of 15.9:1.
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%. The school serves a diverse student body in Crystal Lake, IL.
What is the quality grade for Crystal Lake South High School?
Crystal Lake South High School receives a Resource Quality Grade of C- (51/100) based on 5 factors: student-teacher ratio, AP course offerings, counselor availability, attendance rates. This grade reflects available federal resource indicators, not standardized test scores.
Related data sources
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