D
Needs Improvement
36/100

William Tell Aggeler Opportunity High

📚 07 – 12 🏫 High School
📍 21050 Plummer St., Chatsworth, CA 91311
Overall
D
36/100 · the blend of everything below
Achievement
D
Reading 5% · Math 5% proficient · 9th percentile in California
Graduation
D
10% earn a regular diploma in 4 years
Resources
B
Class size, funding, school size and type

Each score is graded separately against California schools. A school can be strong at moving students forward (growth) without having the highest test scores, or the reverse. How we score schools

36
Repit Score
out of 100
68
Students
enrolled
16.7:1
Student:Teacher
ratio
$26K
Per Student
spending

What Goes Into This Rating

FactorWeightScoreBasis
📚 Academics (reading & math)55%9/100reading 4th percentile, math 14th percentile among California high schools (2018–19 state tests)
🎓 Graduation (4-year, diploma only)25%1/10010% graduate on time with a regular diploma
🏫 Resources (class size, funding, size, type)20%75/100Inputs from NCES school and district data

Students served: 48% students directly certified for free meals (their families receive SNAP or similar aid). Compared with California schools serving a similar share of low-income students, this school’s reading and math results are −37 points worse than expected. (Context only; not part of the score.)

The overall Repit Score ranks this blend against every rated school in California. Schools are compared within their state because each state sets its own tests and proficiency bar. How we rate schools

Test Scores & Graduation

📖 Reading proficiency5% (−43 pts vs. state avg 48%)
Students scoring proficient on the state test, 2018–19
➗ Math proficiency5% (−32 pts vs. state avg 37%)
Students scoring proficient on the state test, 2018–19
🎓 Graduation rate10% (−66 pts vs. state avg 76%)
Four-year adjusted cohort graduation rate, class of 2020

Source: U.S. Department of Education EDFacts via the Urban Institute Education Data Portal. Federal reporting rounds small schools to ranges; we show the midpoint. Proficiency standards differ by state, so compare schools within the same state.

How Student Groups Do Here

Share of each group of students scoring proficient on the California state test (2018–19), compared with the same group of students across the state. Differences between groups are shown as reported; they reflect many factors inside and outside school.

StudentsReadingMathvs. same group statewideRank in state for this group
Hispanic5%5%reading -41 pts, math -16 pts4th percentile (list)
Low-income5%5%reading -40 pts, math -17 pts4th percentile (list)

Source: U.S. Department of Education EDFacts via the Urban Institute. Groups with fewer than 20 tested students are not shown. Results are achievement (proficiency), not growth; growth by group is not published for individual schools.

School Information

Address 21050 Plummer St.
City Chatsworth
ZIP Code 91311
District 0622710
NCES School ID 062271002802
Data Year 2024-25

Community Context for 91311

Understanding the community around William Tell Aggeler Opportunity High helps evaluate the school environment and neighborhood.

💰 Income & Economy

Median Household Income $112,172
Per Capita Income $51,418
Poverty Rate 3.4%
Households Earning $100K+ 56.2%

🎓 Education Level

Bachelor's Degree or Higher 43.7%
High School or Higher 91.7%

🏠 Housing

Median Home Value $789,500
Median Rent $2,154
Owner-Occupied 66.1%
Renter-Occupied 33.9%
View full data for ZIP 91311 →

Thinking about moving into this school’s area? See what homes and rents actually cost in ZIP 91311 — values, rent, and how it compares to nearby ZIPs. Free, no signup. See 91311 housing costs →

Student Demographics

Enrollment and demographic breakdown for William Tell Aggeler Opportunity High.

👫 Gender Distribution

Male 64.7%
Female 35.3%

🌎 Race & Ethnicity

Hispanic/Latino 88.2%
White 4.4%
Black 2.9%
Two or More Races 2.9%
Asian 1.5%

📋 Enrollment Summary

Total Enrollment 68
Teachers (FTE) 4.1
Student:Teacher Ratio 16.7:1

Frequently Asked Questions

What is the Repit School Score for William Tell Aggeler Opportunity High?
William Tell Aggeler Opportunity High has a Repit School Score of 36 out of 100, earning a grade of D. The score is based mainly on reading and math proficiency compared with other schools in the state, plus the on-time graduation rate, with class size and funding counting for a smaller share.
How many students attend William Tell Aggeler Opportunity High?
William Tell Aggeler Opportunity High has 68 students enrolled for the 2024-25 school year. The student-to-teacher ratio is 16.7:1.
What grades does William Tell Aggeler Opportunity High serve?
William Tell Aggeler Opportunity High serves grades 07 – 12 and is classified as a High School. This is a public school.
How much funding does William Tell Aggeler Opportunity High receive per student?
William Tell Aggeler Opportunity High receives $25,877 in per-pupil spending from its district. This is above the national average.
🏠 Rental Market Around William Tell Aggeler Opportunity High in 91311 ▼
Avg Home Value
$941,301
Avg Monthly Rent
$2,840
1-Year Change
+1.8%
% Renters
33.9%

Other Schools in 91311

View all schools and real estate data for 91311 →

About Repit School Scores

Parents choosing a school deserve to see what it actually delivers. Since October 2026 the Repit School Score is built mainly on results:

  • Academics (largest share) — the share of students scoring proficient in reading and math on the state test, ranked against schools of the same level in the same state.
  • Graduation (high schools) — the four-year adjusted cohort graduation rate. Only regular diplomas count; GEDs and certificates of attendance do not.
  • Resources (smaller share) — class size, per-pupil funding, school size and type.

Scores compare schools within their own state, because every state writes its own tests and sets its own proficiency bar. Full methodology

Data sources: NCES CCD 2024-25, U.S. Dept. of Education EDFacts (test results & graduation) | Last updated: October 2026