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Email BoardDiamond Bar High
21400 Pathfinder Road, Diamond Bar, CA 91765-2747
Summary
Diamond Bar High is a good school.
Reading and math results average to the 94th percentile among comparable California schools.
78.2% of students met California's reading standard, and it is holding steady.
67.8% of students met California's math standard, but it is trending up slightly.
Proficiency stats
| Current Reading Proficiency | 78.2% |
| Current Math Proficiency | 67.8% |
| Reading State Rank | 156/1,596 (90th percentile) |
| Math State Rank | 52/1,596 (97th percentile) |
School information
| Student / Teacher Ratio | 26:1 |
| Student enrollment (2024–25) | 2,563 |
| Low-Income Students | 584 (22.8%) |
| English Learners | 189 (7.4%) |
School Website
Great Schools
Niche
Ed-Data
CAASPP| Admissions | Open enrollment |
|---|---|
| Charter school | No |
| Magnet school | No |
Test score trends
Reading rose 1.9 points from last year and rose 0.2 points over the full period. Math fell 0.5 points from last year and rose 1.1 points over the full period.
•Math +1.1 percentage points (2024–2026)Reading Proficiency Scores
2026 state test results
Race and Ethnicity
Most students in every reported group meet the reading standard. Two or more races and Asian students have the strongest results.
Distribution of Scores by Grade
78.2% of tested students meet the reading standard in the grade shown. Overall, the school’s reading results rank in the top 10% among California schools in the same grade-level category.
Low-Income vs Non-Low-Income
The 12.8-point reading income gap is narrower than the 14.7-point gap at a typical California 9–12 school. It widened over the period shown.
•English Learners vs English Native
0.0% of English learners meet the reading standard, compared with 84.1% of English-only students. The gap widened as English-learner results fell and English-only results rose.
•Math Proficiency Scores
2026 state test results
Race and Ethnicity
Asian students have the strongest math results at about 77% proficiency. The other reported groups range from about 41% to 75%.
Distribution of Scores by Grade
67.8% of tested students meet the math standard in the grade shown. Overall, the school’s math results rank in the top 4% among California schools in the same grade-level category.
Low-Income vs Non-Low-Income
The 3.0-point math income gap is narrower than the 14.2-point gap at a typical California 9–12 school. It narrowed over the period shown.
•English Learners vs English Native
35.7% of English learners meet the math standard, compared with 61.9% of English-only students. The gap narrowed as English-learner results rose and English-only results rose.
•How we compare income gaps
“Typical” means the median gap across 876 schools for reading and 882 for math. The comparison uses 2026 California 9–12 schools with at least 20 tested students in each income group and a reported low-income student population. Each school counts once. Its gap is non-low-income proficiency minus low-income proficiency, including negative gaps. California state test data
Understanding this school
How does Diamond Bar High compare within the district?
Diamond Bar High is No. 2 in reading and No. 1 in math proficiency among the 2 9–12 schools in Walnut Valley Unified with 2026 results.
Explore the district’s schoolsHow does Diamond Bar High rank in California?
Diamond Bar High ranks No. 156 of 1,596 in reading and No. 52 of 1,596 in math for 2026. These proficiency rankings compare California schools in the same grade-level category.
How do low-income students at Diamond Bar High compare within the district?
Low-income students here rank No. 2 in reading and No. 1 in math among 2 9–12 district schools with reportable 2026 results for this group. 68.5% meet the reading standard and 65.5% meet the math standard.
See results by student groupHow does Diamond Bar High compare with other schools in Los Angeles County?
Diamond Bar High is No. 45 in reading and No. 10 in math proficiency among the 334 9–12 schools in Los Angeles County with 2026 results.
Explore schools in Los Angeles CountyWhich schools should I compare?
Schools serving 9–12 in the same district.
| School | Math | Reading |
|---|---|---|
| Diamond Bar HighThis school | 67.8% | 78.2% |
| Walnut High | 61.9% | 80.4% |
