Cos Cob School vs Greenwich High School
A head-to-head comparison of two schools in Connecticut, United States, 1.2 km apart, using official American 2025 data. The better value in each row is highlighted.
Cos Cob School
Cos Cob · Public elementary · Grades PK–5
343 students
Greenwich High School
Greenwich · Public high · Grades 9–12
2,620 students
| Measure | Cos Cob School Cos Cob, Connecticut | Greenwich High School Greenwich, Connecticut |
|---|---|---|
| Success Index (US) | 89 Top 5% | 82 Top 10% |
| State rank | #74 of 596 | #36 of 180 |
| National rank | #908 of 50,301 | #960 of 16,910 |
| Sector | Public | Public |
| Type | Elementary | High |
| Year range | Grades PK–5 | Grades 9–12 |
| Students | 343 | 2,620 |
| Enrollment | 343 | 2,620 |
| Free/reduced-price lunch | 16% | 22.8% |
| Students per teacher | 10.1 | 13.4 |
| Reading proficiency | 72% | 83% |
| Math proficiency | 74% | 66% |
| city | Cos Cob | Greenwich |
| state | Connecticut | Connecticut |
| Website | – | – |
The verdict
- •Cos Cob School scores higher on the Success Index (US) (89.4 vs 82.4).
- •Cos Cob School does better on math proficiency (74% vs 66%).
- •Greenwich High School does better on reading proficiency (83% vs 72%).
- •Cos Cob School does better on community advantage (fewer free/reduced-price lunch) (16% vs 22.8%).
- •Cos Cob School does better on students per teacher (10.1 vs 13.4).
- •Greenwich High School is the larger school with 2,620 students compared with 343.
The Success Index (US) summarises published results and context from official data. It does not measure teaching quality or fit. Methodology.
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Frequently asked questions
Is Cos Cob School better than Greenwich High School?
On the Success Index (US), Cos Cob School ranks higher (89.4 vs 82.4 out of 100). The index is built from published results and context data, not from teaching quality or fit, so visit both schools before deciding.
How far apart are Cos Cob School and Greenwich High School?
About 1.2 km in a straight line, between Cos Cob and Greenwich in Connecticut.
Which has the better Enrollment?
Cos Cob School: 343. Greenwich High School: 2,620. Students enrolled in the latest NCES directory year.
How do Cos Cob School and Greenwich High School rank in Connecticut?
Cos Cob School is 74th of 596 and Greenwich High School is 36th of 180 among elementary schools in Connecticut on the 2025 Success Index (US).