1
What's the vibe like in the hallways at Los Osos High right now?
Community prompt from u/allk12. Replies below.
Enrollment
2,759
High
DISTRICT 2,004 · STATE 838
SCHOOL COMMUNITY·CHAFFEY JOINT UNION HIGH·NCES 060816010605
Los Osos High
6001 Milliken Ave., Rancho Cucamonga, CA 91737 · (909) 477-6900 · San Bernardino County
GRADES 09–12HIGH21-SUBURBTITLE IREGULAR SCHOOL2,759 STUDENTS
A
allk12 Grade
Scored higher than 87% of California public high schools
- ATest scores Share of students meeting the state standard in reading, math, and other tested subjects, 2023-24 and 2024-25.
- A-Beats expectations How far test scores land above or below what the share of low-income students predicts for a school in this state.
- C-Three-year trend Change in reading and math proficiency over the last three test years.
Grades compare a school only with schools in the same state, because every state gives its own test. How grades work · Top-graded California public high schools
Student : Teacher
25.8:1
107 FTE teachers
DISTRICT 21.6:1 · STATE 18.2:1
Free / Reduced Lunch
44%
1,206 students
DISTRICT 70% · STATE 65%
Community
6
0 members
Enrollment and student:teacher ratio compared against other high schools. Free/Reduced Lunch and demographics compared against all schools.
Enrollment by grade, 2024-25
| Grade | Students | Share |
|---|---|---|
| Grade 9 | 721 | 26% |
| Grade 10 | 655 | 24% |
| Grade 11 | 685 | 25% |
| Grade 12 | 698 | 25% |
Student demographics
71%Diversity index
The chance that two students picked at random belong to different racial or ethnic groups.
DISTRICT 55% · STATE 62% · US 70%
Student head counts by race/ethnicity from federal NCES enrollment data. District, state, and US figures are each group's share of all public school students in that area (US excludes territories). Very small groups may be suppressed in the source, so categories do not always sum exactly to total enrollment.
Gender split
Test scores
CAASPP 2024-25 . % met or exceeded standardEnglish Language Arts
79.0%
CA avg 49.1% . +7.0pp since 2014
Math
50.9%
CA avg 37.7% . -2.1pp since 2014
What this means: On the CAASPP, California's statewide test, about 79 of every 100 students at this school read and write at grade level and about 51 of 100 do math at grade level. Across all California schools, those numbers are about 49 and 38. Reading and writing scores are up about 7 points since 2014, while math scores are down about 2 points.
Performance levels, 2024-25
| Subject | Standard Exceeded | Standard Met | Standard Nearly Met | Standard Not Met |
|---|---|---|---|---|
| English Language Arts | 50.8% | 28.2% | 13.6% | 7.4% |
| Math | 28.2% | 22.7% | 22.9% | 26.3% |
Share of tested students at each CAASPP level. Each student counts in one level, so a row adds to about 100%.
CAASPP results by year
| School year | English Language Arts | Math |
|---|---|---|
| 2024-25 | 79.0% | 50.9% |
| 2023-24 | 81.8% | 48.6% |
| 2022-23 | 78.8% | 51.4% |
| 2021-22 | 81.6% | 52.5% |
| 2020-21 | 77.3% | 63.9% |
| 2018-19 | 81.2% | 57.8% |
| 2017-18 | 74.5% | 53.4% |
| 2016-17 | 70.5% | 51.9% |
| 2015-16 | 80.0% | 55.0% |
| 2014-15 | 72.0% | 53.0% |
% met or exceeded standard, all students and all tested grades.
Source: CAASPP. All students, all grades. See all years and grades →
BeatsExpectations
Demographically-adjusted score · methodologyTier
AS EXPECTED
Performing as predicted given the school's student profile
Actual proficiency
65.1%
composite math + reading, all grades
Predicted
53.9%
based on CA schools with similar FRL share
Beats by
+11.1pp
above demographic expectation
What this means: About 65% of students here test proficient in math and reading, compared with the roughly 54% typical for California schools with a similar share of low-income students. BeatsExpectations measures results against demographically similar schools rather than by raw scores, and this school falls within the typical range, neither among California's top nor bottom 10%.
BeatsExpectations runs a per-state regression of proficiency on free/reduced-lunch share, then scores each school by residual. How this is calculated →
Schools most like Los Osos High
Los Osos High's state test result (65.1% proficient) is higher than 4 of the 5 schools below with a result.
| School | Students | Low-income | Proficient |
|---|---|---|---|
| Los Osos High this school | 2,759 | 43.7% | 65.1% |
| Stockdale High Bakersfield | 2,398 | 44.3% | 54.7% |
| Westmont High Campbell | 1,682 | 42.0% | 58.8% |
| Chaparral High Temecula | 3,136 | 39.4% | 56.3% |
| Brea Olinda High Brea | 1,676 | 41.6% | 58.0% |
| Torrance High Torrance | 1,879 | 36.4% | 65.6% |
Matched among California high schools on enrollment, the share of students from low-income families (eligible for free or reduced-price lunch), and racial and ethnic makeup. Proficient is the average share of students meeting the state standard across all of the school's state tests in 2023-24 and 2024-25, the same combined score our test-score rankings use. Online schools and schools serving specialized populations are not matched.
Where Los Osos High ranks
Among high schools| Measure | This school | In California | In San Bernardino County |
|---|---|---|---|
| State test proficiency ranked highest first | 65.1% | #122 of 1,052 | #2 of 54 |
| Math proficiency ranked highest first | 50.9% | #158 of 1,056 ▲ 3 | #3 of 56 ▲ 1 |
| Reading proficiency ranked highest first | 79.0% | #111 of 1,056 ▼ 32 | #3 of 56 ▼ 1 |
| 3-year test score change ranked biggest drop first | -2.1pp | #242 of 1,044 | #5 of 56 |
| Enrollment ranked largest first | 2,759 | #49 of 2,093 | #6 of 102 |
| Students per teacher ranked fewest first | 25.8:1 | #1,260 of 1,352 | #69 of 78 |
| Diversity index ranked most diverse first | 71.0% | #91 of 1,351 | #2 of 77 |
| Free and reduced lunch ranked highest share first | 43.7% | #1,241 of 1,575 | #83 of 84 |
| Enrollment change since 2017-18 ranked steepest decline first | -12.5% | #369 of 802 | #19 of 46 |
Ranked against other public high schools. Online schools are left out of every list, and test-score lists leave out schools that serve specialized populations. Each rank links to the full list. Arrows under a test-score rank show places moved since the prior test year, among schools tested both years.
4-year change
SY 2020-21 vs SY 2024-25Enrollment
2,759
-195 (-7%) vs 2020
-18% since 2010-11, when it was 3,365
Student : Teacher
25.8:1
was 25.3:1
Source: NCES Common Core of Data
Enrollment and staffing by year
| School year | Students | Teachers (FTE) | Students per teacher | Free and reduced lunch |
|---|---|---|---|---|
| 2024-25 | 2,759 | 107.1 | 25.8:1 | 44% (1,206) |
| 2023-24 | 2,759 | 110.8 | 24.9:1 | 34% (950) |
| 2022-23 | 2,837 | 114.5 | 24.8:1 | 29% (822) |
| 2020-21 | 2,954 | 117 | 25.3:1 | 34% (1,001) |
| 2017-18 | 3,153 | 121.3 | 26.0:1 | 33% (1,051) |
| 2015-16 | 3,198 | 116 | 27.6:1 | 33% (1,043) |
| 2010-11 | 3,365 | N/A | N/A | 18% (591) |
Source: NCES Common Core of Data. Rows are the federal collections on file for Los Osos High.
Since 2017-18: students down 12% (3,153 to 2,759); teachers down 12% (121.3 to 107.1).
About Los Osos High
The public high school Los Osos High is located in Rancho Cucamonga, California. It is open to students in grades 9 through 12 and enrolls 2,759 students. That is 229% larger than the average of about 838 students for high schools in California.
Chaffey Joint Union High has a total of 11 schools and 22,040 students, Los Osos High among them.
Hispanic students account for 41% of enrollment at Los Osos High, more than any other group. Other groups make up 24% White, 23% Asian, 6% Black, and 5% multiracial. County-wide, 55% of San Bernardino County residents are Hispanic. Measured by the diversity index, the student body scores 71%.
Los Osos High reports a ratio of 25.8 students per teacher, from 107.1 full-time-equivalent teachers. The school's 25.8:1 compares with an average of 18.2:1 for high schools in California. Lunch program data show 44% of students are eligible for free or reduced-price meals. The gap from the 74% average for public schools in San Bernardino County is 30 points.
Los Osos High holds an A allk12 Grade, placing it above 87% of California public high schools.
On the allk12 BeatsExpectations measure, Los Osos High is 11.1 points above the average proficiency rate across its state test results predicted for its free or reduced-price lunch share: 65.1% actual, 53.9% predicted. That is outside both the top and bottom 10% in California.
San Bernardino County is the school's county. There, the median household earns about $85,478 a year, roughly 23% of adults have a four-year degree or more, and about 11% of residents live below the federal poverty line. Public schools in San Bernardino County number 583, with about 393,648 students.
Caryn Elementary, about 0.4 miles away, is the closest public school. A five-mile radius around the school includes at least 8 other public schools. On state test proficiency, Los Osos High ranks 5th in a group of 9 nearby schools.
Federal records code the school's setting as Suburb: Large.
Over the 4 years from 2020-21 to 2024-25, enrollment decreased 7%.
The discussion board for Los Osos High is open to topics like athletics, class schedules, and weather closures. Parents, students, alumni, and staff are welcome to post.
San Bernardino County at a glance
View full county profilePopulation
2,197,104
Census ACS
Median income
$85,478
Household, ACS
Bachelor's+
23%
Adults 25+
Poverty rate
11%
Below federal line
Schools in county
583
393,648 students
Quick facts
Related schools
Other schools in Chaffey Joint Union High
- Etiwanda HighHigh · 3,446 students
- Rancho Cucamonga HighHigh · 3,221 students
- Chaffey HighHigh · 3,127 students
- Montclair HighHigh · 2,515 students
- Alta Loma HighHigh · 2,386 students
- Colony HighHigh · 2,109 students
Other schools in Rancho Cucamonga
- Rancho Cucamonga HighHigh · 3,221 students
- Ruth Musser MiddleMiddle · 941 students
- Terra Vista ElementaryElementary · 855 students
- Coyote Canyon ElementaryElementary · 817 students
- Rancho Cucamonga MiddleMiddle · 770 students
- Cucamonga MiddleMiddle · 662 students
Nearby schools
- Caryn Elementary0.4 mi · 553
- Banyan Elementary0.6 mi · 572
- Rancho Cucamonga High1.1 mi · 3,221
- Victoria Groves Elementary1.2 mi · 452
- Carleton P. Lightfoot Elementary1.2 mi · 878
- John L. Golden Elementary1.3 mi · 916
Frequently asked questions
About Los Osos HighWhat is the total enrollment at Los Osos High?
Los Osos High enrolls approximately 2,759 students in grades 09-12.
What grades does Los Osos High serve?
Los Osos High serves grades 09-12.
How many students per teacher at Los Osos High?
Approximately 25.8:1 students per teacher at Los Osos High.
How diverse is Los Osos High?
Los Osos High reports a student body of 24% White, 41% Hispanic, 6% Black, 23% Asian, 5% Two or more.
Is Los Osos High public or private?
Los Osos High is a public K-12 school, overseen by Chaffey Joint Union High.
Data sourceSchool profile facts are sourced from the NCES. Community content is posted by allk12 members.