Very Good
#1761 of 4,739 schools in NY
Top 37% in state
Robert M Grable JR Mount Sinai High School
High School · MOUNT SINAI UNION FREE SCHOOL DISTRICT
110 N COUNTRY RD, Mount Sinai, NY 11766
Enrollment
700
Student-Teacher
11.9:1
Score
7.0
Grades
9th – 12th
Enrollment
700
Student-Teacher
11.9:1
Score
7.0
Grades
9th – 12th
Updated
2022-23
Updated 2022-23
How this school compares
In Mount Sinai
#2 of 3
public schools
New York high schools
#448 of 1,160
In district
#2 of 3
MOUNT SINAI UNION FREE SCHOOL DISTRICT
Academic performance
8.6 / 10
Exceptional
About Robert M Grable JR Mount Sinai High School
Robert M. Grable Jr. Mount Sinai High School serves 700 students in grades 9-12 in Mount Sinai, New York, with a favorable student-teacher ratio of 11.9:1 among its 59 full-time equivalent teachers.
The school demonstrates strong academic performance, earning a 7.1 out of 10 MySchoolScout rating and ranking in the 75th percentile among New York high schools at #1176 out of 4,758 schools statewide. Students excel particularly in mathematics, with an impressive 98% achieving proficiency or above across grade levels, while 82% demonstrate proficiency in English Language Arts and reading. These results contribute to the school's solid 8.6 out of 10 academic score, reflecting consistent student achievement across core subjects.
The school draws from an affluent community where the median household income reaches $146,042 and nearly half of residents hold bachelor's degrees or higher. With a remarkably low poverty rate of just 1.8% and median home values around $590,000, the ZIP code 11766 represents one of the more prosperous areas in Suffolk County. Mount Sinai High School operates within a large suburban setting that combines the benefits of a close-knit Long Island community with access to broader educational and cultural resources throughout the region.
Score Breakdown
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Robert M Grable JR Mount Sinai High School — Students at Robert M Grable JR Mount Sinai High School score 82% proficient, which is above what's typical for similar communities (expected: 71%).
Equity & Diversity
Shown separately, not included in overall scoreFree/Reduced Lunch
11.6%
Students qualifying for federal meal assistance
Test Scores NY EDFACTS (2020-21)
Based on 4 test records from NY state assessments. About our data
Proficiency Trend
↓ DecliningAverage proficiency (% at or above grade level) across Math & ELA over time.
* COVID-affected year — test participation was uneven nationwide. This data is weighted at 50% in the Growth score calculation.
Source: EdFacts (NCES) and state assessment data. Growth score: 2.8/10.
How Robert M Grable JR Mount Sinai High School Compares
See how Robert M Grable JR Mount Sinai High School performs across key quality dimensions compared to state benchmarks.
Funding & Resources
Performance Trends
Math proficiency has remained stable from 98% (2019) to 97.5% (2021). Reading/ELA proficiency has declined from 97.5% (2019) to 67% (2021).
Location
110 N COUNTRY RD, Mount Sinai, NY 11766
Nearby Alternatives
Families considering Robert M Grable JR Mount Sinai High School may also want to explore other high schools in the area. WARD MELVILLE SENIOR HIGH SCHOOL (rated 8.7/10, 3.0 miles away, in nearby East Setauket), which scores notably higher. Another option is EARL L VANDERMEULEN HIGH SCHOOL (rated 8.6/10, 2.2 miles away, in nearby Port Jefferson), which scores notably higher. Additionally, MILLER PLACE HIGH SCHOOL (rated 7.3/10, 2.0 miles away, in nearby Miller Place), with a very similar rating. For more schools in Mount Sinai, see our Mount Sinai schools guide .
Nearby Schools
20 within 4.2 mi| School | Distance | Rating |
|---|---|---|
| MOUNT SINAI MIDDLE SCHOOL Mount Sinai | 0.2 mi | 5.7 |
| MOUNT SINAI ELEMENTARY SCHOOL Mount Sinai | 0.4 mi | 8.4 |
| PORT JEFFERSON ELEMENTARY SCHOOL Port Jefferson | 1.5 mi | 6.3 |
| JOHN F KENNEDY MIDDLE SCHOOL Port Jefferson Station | 2.0 mi | 4.7 |
| COMSEWOGUE HIGH SCHOOL Port Jefferson Station | 2.2 mi | 6.6 |
| MILLER PLACE HIGH SCHOOL Miller Place | 2.0 mi | 7.3 |
| CLINTON AVENUE SCHOOL Port Jefferson Station | 2.5 mi | 5.3 |
| TERRYVILLE ROAD SCHOOL Port Jefferson Station | 2.5 mi | 7.2 |
| NORTH COUNTRY ROAD SCHOOL Miller Place | 2.2 mi | 6.7 |
| SOUND BEACH SCHOOL Miller Place | 2.4 mi | 7.7 |
| EARL L VANDERMEULEN HIGH SCHOOL Port Jefferson | 2.2 mi | 8.6 |
| PORT JEFFERSON MIDDLE SCHOOL Port Jefferson | 2.3 mi | 8.0 |
| ANDREW MULLER PRIMARY SCHOOL Miller Place | 2.5 mi | 7.1 |
| NORWOOD AVENUE SCHOOL Port Jefferson Station | 2.7 mi | 6.7 |
| BOYLE ROAD ELEMENTARY SCHOOL Port Jefferson Station | 3.3 mi | 8.3 |
| WARD MELVILLE SENIOR HIGH SCHOOL East Setauket | 3.0 mi | 8.7 |
| ARROWHEAD ELEMENTARY SCHOOL East Setauket | 3.1 mi | 8.6 |
| STAGECOACH SCHOOL Selden | 4.2 mi | 7.8 |
| HAWKINS PATH SCHOOL Selden | 4.3 mi | 8.0 |
| WEST MIDDLE ISLAND SCHOOL Middle Island | 4.2 mi | 4.1 |
Neighborhood Census ACS (2019-2023)
Census data for ZIP 11766 (ACS 2019-2023 5-Year Estimates) · Data sources
Median Income
$157,564
Median Home Value
$632,900
Median Rent
$3,183/mo
Population
11,481
College Educated
51.3%
Homeownership
96.9%
Avg Commute
34.3 min
Poverty Rate
1.9%
Median Age
47.7
Community Profile
The community surrounding Robert M Grable JR Mount Sinai High School has a median household income of $157,564. It is a well-educated community where 51% of adults hold a bachelor's degree or higher. The median home value in the area is $632,900, with a median rent of $3,183/month. The local poverty rate of 1.9% is relatively low. The average commute for residents is 34 minutes. Source: U.S. Census ACS 2022 5-Year Estimates.
Similar Schools
Schools in the same state with comparable level, size, and ratings
| School | Rating |
|---|---|
| BENJAMIN BANNEKER ACADEMY Brooklyn, NY | 7.0 |
| BRONX HIGH SCHOOL FOR THE VISUAL ARTS Bronx, NY | 7.0 |
| BROOKLYN INSTITUTE FOR LIBERAL ARTS Brooklyn, NY | 7.0 |
| CSI HIGH SCHOOL FOR INTERNATIONAL STUDIES Staten Island, NY | 7.0 |
| HUDSON HIGH SCHOOL Hudson, NY | 7.0 |
| INDIAN RIVER HIGH SCHOOL Philadelphia, NY | 7.0 |
Frequently Asked Questions
Common questions about Robert M Grable JR Mount Sinai High School
What grades does Robert M Grable JR Mount Sinai High School serve?
Robert M Grable JR Mount Sinai High School serves students in grades 9th through 12th.
How many students attend Robert M Grable JR Mount Sinai High School?
Robert M Grable JR Mount Sinai High School has an enrollment of approximately 700 students.
What is the student-teacher ratio at Robert M Grable JR Mount Sinai High School?
The student-teacher ratio at Robert M Grable JR Mount Sinai High School is 11.9:1. A lower ratio generally means more individual attention per student. The national average is approximately 16:1 for public schools.
How does Robert M Grable JR Mount Sinai High School rank in NY?
Robert M Grable JR Mount Sinai High School is ranked #1761 out of 4,739 schools in NY.
What is Robert M Grable JR Mount Sinai High School's MySchoolScout rating?
Robert M Grable JR Mount Sinai High School has a composite rating of 7.0 out of 10 on MySchoolScout. This score combines academic performance, student growth, and school environment into a single score. Equity data is shown separately for context.
What are the test scores at Robert M Grable JR Mount Sinai High School?
Based on the most recent state assessment data, Robert M Grable JR Mount Sinai High School has 97.8% math proficiency and 82.3% reading/ELA proficiency.
Is Robert M Grable JR Mount Sinai High School a charter school?
No, Robert M Grable JR Mount Sinai High School is not a charter school. It is a traditional public school operated by the local school district.
Is Robert M Grable JR Mount Sinai High School a Title I school?
No, Robert M Grable JR Mount Sinai High School is not currently a Title I school.
What does the Free & Reduced Lunch percentage mean for Robert M Grable JR Mount Sinai High School?
11.6% of students at Robert M Grable JR Mount Sinai High School qualify for free or reduced-price lunch. This is a commonly used indicator of economic need and provides important context when interpreting test scores.
Neighborhood Context
Powered by 
FBI UCR 2024. County-level only. Data >1 year old.
Quick Facts NCES CCD (SY 2022-23)
- Grades
- 9th – 12th
- Enrollment
- 700
- Student-Teacher Ratio
- 11.9:1
- Teachers (FTE)
- 59
- Free/Reduced Lunch
- 11.6%
- Type
- regular
- Setting
- Large Suburb
- County
- Suffolk County
- Phone
- (631) 870-2800
- Data Year
- 2023–2024
Resources & Links
District
MOUNT SINAI UNION FREE SCHOOL DISTRICT- District Enrollment
- 2,074
- Schools in District
- 3
- Per-Pupil Spending
- $29,270
- District Rank
- #2 of 3
Other Schools in This District
How We Rate Schools
Every school receives a composite score from 1 to 10 based on four pillars: Academic Performance (50%), Student Growth (20%), Equity (15%), and Learning Environment (15%). Scores are built from publicly available data including standardized test results, enrollment figures, and school climate indicators.
Read our full methodologyRelated reading
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- Best Schools in New York, NY — 2026 Rankingsbest schools
- Best States for Public Schools in 2026: A Complete Rankingdata insights
- Charter Schools vs Public Schools: What the Data Actually Shows (2026)school choice
- Student-Teacher Ratio by State: Complete 2026 Rankingsdata insights
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