Type
Boarding and Day
School
St. Mark's School
Siviq Rank#59Southborough, MA • Boarding and Day
Boarding and Day0 AP Courses
Enrollment
373
Student-Teacher Ratio
6:1
Admit Rate
30%
Reach
Global
Narrative
Profile Notes
Summary
St. Mark’s School is an independent Episcopalian boarding and day high school in Southborough, Massachusetts, serving grades 9-12. For 2025-2026, the profile reports 373 students, an average class size of 11, a 6:1 student-faculty ratio, 34% of students receiving financial aid, 37% domestic students of color, and 24% international students. The school offers no AP courses, uses unweighted GPA, does not compute class rank, and reports college matriculation outcomes across 2023-2025.
College Counseling
College Counseling Office includes a Director, Associate Director, Assistant Director, Counselor, and Registrar.
Advanced Coursework
Most rigorous courses are designated Advanced; St. Mark’s does not offer AP classes. Almost all courses are regular/standard or Advanced in level; the only Honors courses are Honors Algebra II and Honors Precalculus. Students have limited opportunities to pursue Advanced-level courses before V Form.
Matriculation Notes
Over the past three years, students have chosen more than 100 colleges and universities. Each year, on average, students matriculate at 60 different schools in more than 20 states, as well as countries outside the US. Virtually all graduates enroll in a four-year institution immediately upon graduation.
Siviq Layer
Siviq Scores
Siviq Scores
Precomputed percentiles relative to similar schools. These scores are descriptive rather than judgmental.
Academic Program
15th percentile
Higher reported academic program than 15% of similar schools.
Combines advanced-course offerings, testing, and reported honors or IB signals.
Average Class Size
27th percentile
Lower reported average class size than 27% of similar schools.
Smaller reported average classes score higher within each peer cohort.
Institutional Resources
74th percentile
Higher reported institutional resources than 74% of similar schools.
Uses linked nonprofit financial capacity when a reviewed EIN match is available.
Outcomes
73rd percentile
Higher reported outcomes than 73% of similar schools.
Based on the reported outcomes evidence available for this school.
Reach & Access
50th percentile
Higher reported reach & access than 50% of similar schools.
Combines geographic reach and reported access signals from the current school data.
Student Experience
67th percentile
Lower reported student experience than 67% of similar schools.
Lower student-teacher ratios score higher within each peer cohort.
Standardized Data
Profile
Profile
Overview
- Grades Served
- 9-12
Profile
Admissions
- Admit Rate
- 30%
Profile
Academics
- AP Courses
- 0
- Honors Program
- Yes
Profile
Student Body
- States Represented
- 20
- Countries Represented
- 17
- Students of Color
- 37%
- International Students
- 24%
- Receiving Financial Aid
- 34%
Profile
Policies
- Class Rank Policy
- St. Mark’s does not compute class rank or release individual GPAs to colleges.
- Weighted Grades
- No
- Weighted Grades Policy
- GPAs are unweighted and include only courses taken at St. Mark’s School.
- Disciplinary Reporting
- Yes
Linked Nonprofit Data
Nonprofit Financials
Net Assets
$196,705,316
Tax year 2024
Net Income
-$10,827,836
Latest revenue minus expenses from the school's nonprofit filing.
Total Expenses
$47,831,333
Tax year 2024
Expenses Per Student
$128,234
Calculated from total expenses divided by the current school-profile enrollment.
Location Context
Nearest
Institutional Details
People & Credentials
Institutional
Leadership
Head of School
Dr. Ivory Hills
Assistant Head of School, Dean of Academics
Christina Kennedy
Institutional
Contacts
Director
Eric R. Monheim
Associate Director
Nora Guyer
Assistant Director
Jillian Greenspan
Counselor
Joelle Gilmore
Registrar
Claire Messier
Main School Office
St. Mark’s School
25 Marlboro Road, Southborough, MA 01772; Fax: 508-786-4083
Institutional
School Codes
CEEB code
221965
External References
Links
Search & Answers
St. Mark's School Frequently Asked Questions
What is the student-teacher ratio at St. Mark's School?
The current school profile reports a student-teacher ratio of 6:1 at St. Mark's School.
How many students are enrolled at St. Mark's School?
The current school profile reports about 373 students enrolled at St. Mark's School.
What grades does St. Mark's School offer?
St. Mark's School currently reports serving grades 9-12.
Where is St. Mark's School located?
St. Mark's School is located in Southborough, MA.
Is St. Mark's School a day school or a boarding school?
St. Mark's School is a private school.
Does St. Mark's School offer advanced placement (AP) courses?
No. The current school profile does not report AP courses at St. Mark's School.
How many students receive financial aid at St. Mark's School?
The current school profile says about 34.0% of students at St. Mark's School receive financial aid.
Does St. Mark’s rank students or send individual GPAs to colleges?
No. St. Mark’s does not compute class rank or release individual GPAs to colleges, and its GPAs are unweighted.
How many classes do students usually take each semester?
The standard load is five classes per semester. With approval from the Academics Office, a student may take six.
What does financial aid look like at St. Mark’s?
The profile says 34% of students receive financial aid. The average award is $58,375 for boarding students and $35,695 for day students.
How broad are St. Mark’s college outcomes?
Over the past three years, students have gone on to more than 100 colleges and universities. In a typical year, they matriculate at 60 different schools in more than 20 states, plus countries outside the U.S., and virtually all graduates enroll in a four-year college right away.
By Geography
Nearby Schools
By Similarity
Similar Schools
Provenance
Sources
| Source | Type | Checked | Metrics |
|---|---|---|---|
| 2025-2026 School Profile (PDF) Used for normalized profile metrics, school facts, FAQ answers, and school SEO metadata. | School Profile PDF | Apr 02, 2026 | AP Courses • Academic Rigor Category • Access Category • Admit Rate • Advanced Course Notes • Average Class Size • More normalized profile fields |
| 2025-2026 school profile PDF resources.finalsite.net/images/v1760966466/stmarksschool/fvlfcrqoy9q2uxracn5t/2025-2026profile.pdf | Official Linked File | May 12, 2026 | States Represented |
| About - St. Mark's School www.stmarksschool.org/about | Official Website Page | May 12, 2026 | Countries Represented • Founded Year |
| College Counseling - St. Mark's School www.stmarksschool.org/academics/college-counseling | Official Website Page | May 12, 2026 | Admit Rate |
| History - St. Mark's School www.stmarksschool.org/about/history | Official Website Page | Apr 05, 2026 | Faculty Count |
| Home - St. Mark's School www.stmarksschool.org | Official Website Page | Apr 05, 2026 | Average Class Size |
Sources & Data QualityMirrored artifacts, website inventory, and normalization review notes for this school profile.
Source Links
Known Website Addresses
| Role | URL | Method |
|---|---|---|
| official_website | www.stmarksschool.org/about/at-a-glance | supplemental_backfill |
| official_website | www.stmarksschool.org/about/facts | supplemental_backfill |
| Fast Facts - St. Mark's School | www.stmarksschool.org/about/fast-facts | supplemental_backfill |
| official_website | www.stmarksschool.org/about/quick-facts | supplemental_backfill |
| Academics - St. Mark's School | www.stmarksschool.org/academics | supplemental_backfill |
| College Counseling - St. Mark's School | www.stmarksschool.org/academics/college-counseling | supplemental_backfill |
| Admission - St. Mark's School | www.stmarksschool.org/admission | supplemental_backfill |
| official_website | www.stmarksschool.org/admissions | supplemental_backfill |
| official_website | www.stmarksschool.org/student-life | supplemental_backfill |
| official_website | www.stmarksschool.org/tuition-and-financial-aid | supplemental_backfill |
| Matriculation List and School Profile - St. Mark's School | www.stmarksschool.org/academics/college-counseling/matriculation-list-and-school-profile | site_scan |
| 2025-2026 school profile PDF | resources.finalsite.net/images/v1760966466/stmarksschool/fvlfcrqoy9q2uxracn5t/2025-2026profile.pdf | page_scan |
| About - St. Mark's School | www.stmarksschool.org/about | supplemental_backfill |
| Calendar - St. Mark's School 2022 | www.stmarksschool.org/about/calendar | supplemental_backfill |
| Home - St. Mark's School | www.stmarksschool.org | existing |
| History - St. Mark's School | www.stmarksschool.org/about/history | supplemental_backfill |
| Leadership - St. Mark's School | www.stmarksschool.org/about/leadership | supplemental_backfill |
| Mission and Values - St. Mark's School | www.stmarksschool.org/about/mission-and-values | supplemental_backfill |
| News and Stories - St. Mark's School | www.stmarksschool.org/about/news-and-stories | supplemental_backfill |
All Canonical Metrics
| Metric | Value | Evidence |
|---|---|---|
| Grades Served | 9-12 | Our classes are traditionally referred to as forms: 9th grade is III Form, 10th grade is IV Form, 11th grade is V Form, and 12th grade is VI Form. |
| Lowest Grade | 9 | 9-12 |
| Highest Grade | 12 | 9-12 |
| Postgraduate Offered | - | 9-12 |
| Boarding Status | Boarding and Day | St. Mark’s is an independent Episcopalian boarding and day high school located 25 miles west of Boston. |
| Boarding Status Code | boarding_and_day | Boarding and Day |
| School Type | Private | St. Mark’s is an independent Episcopalian boarding and day high school located 25 miles west of Boston. |
| School Type Code | private | Private |
| Enrollment | 373 | TOTAL ENROLLMENT 373 |
| Residential Enrollment | - | - |
| Day Enrollment | - | - |
| Student-Teacher Ratio | 6 | Student-to-faculty ratio: 6:1 |
| Founded Year | 1865 | Founded in 1865 |
| School Leadership | - | Dr. Ivory Hills — Head of School |
| Key Contacts | - | College Counseling Office — Eric R. Monheim, Director, [email protected], 508-786-6251 |
| Accreditations | - | - |
| School Codes | - | CEEB code: 221965 |
| AP Courses | 0 | Our most rigorous courses are designated Advanced; we do not offer AP classes. |
| Average Class Size | 25 | Average class size 25 |
| IB Program | - | - |
| Honors Program | Yes | Almost all courses are regular/standard or Advanced in level; the only two Honors-level courses are offered by the math department: Honors Algebra II, and Honors Precalculus. |
| Advanced Course Notes | Most rigorous courses are designated Advanced; St. Mark’s does not offer AP classes. Almost all courses are regular/standard or Advanced in level; the only Honors courses are Honors Algebra II and Honors Precalculus. Students have limited opportunities to pursue Advanced-level courses before V Form. | Our most rigorous courses are designated Advanced; we do not offer AP classes. Almost all courses are regular/standard or Advanced in level; the only two Honors-level courses are offered by the math department: Honors Algebra II, and Honors Precalculus. No other Honors courses are available to students. Students have limited opportunities to pursue Advanced-level courses before V Form. |
| Faculty Count | 80 | 80 faculty members |
| College Counseling Summary | College Counseling Office includes a Director, Associate Director, Assistant Director, Counselor, and Registrar. | College Counseling Office: Eric R. Monheim, Director; Nora Guyer, Associate Director; Jillian Greenspan, Assistant Director; Joelle Gilmore, Counselor; Claire Messier, Registrar. |
| Testing Policy | - | - |
| Testing Policy Code | - | - |
| Average SAT | - | - |
| Average ACT | - | - |
| Matriculation Summary | Over the past three years, students have chosen more than 100 colleges and universities. Each year, on average, students matriculate at 60 different schools in more than 20 states, as well as countries outside the US. Virtually all graduates enroll in a four-year institution immediately upon graduation. | College Matriculation: 2023–2025. Over the past three years, St. Mark’s students have chosen to attend the more than 100 colleges and universities listed below. Each year, on average, students matriculate at 60 different schools in more than 20 states, as well as countries outside the US. Virtually all St. Mark’s graduates enroll in a four-year institution immediately upon graduation. |
| Top Colleges | - | - |
| States Represented | 20 | 20 states |
| Countries Represented | 17 | 17 Countries |
| Students of Color | 37 | 37% domestic students of color |
| International Students | 24 | 24% international students |
| Receiving Financial Aid | 34 | 34% receiving financial aid |
| Tuition-Free Share | - | - |
| Applicants | - | - |
| Admitted | - | - |
| Matriculated | - | - |
| Admit Rate | 30 | admit rates of 30% |
| Yield Rate | - | - |
| Class Rank Policy | St. Mark’s does not compute class rank or release individual GPAs to colleges. | The GPAs above are unweighted and include only courses taken at St. Mark’s School. St. Mark’s does not compute class rank or release individual GPAs to colleges. |
| Class Rank Policy Code | not_reported | St. Mark’s does not compute class rank or release individual GPAs to colleges. |
| Weighted Grades | No | The GPAs above are unweighted and include only courses taken at St. Mark’s School. |
| Weighted Grades Policy | GPAs are unweighted and include only courses taken at St. Mark’s School. | The GPAs above are unweighted and include only courses taken at St. Mark’s School. |
| Disciplinary Reporting | Yes | Policy on Reporting of Discipline: St. Mark’s students are required to respond honestly to questions about their disciplinary history. |
| Boarding Model | boarding_and_day | boarding_and_day |
| Selectivity Category | limited_evidence | limited_evidence |
| Academic Rigor Category | moderate | moderate |
| Testing Policy Category | not_reported | not_reported |
| College Counseling Category | extensive | extensive |
| Student Body Reach Category | global | global |
| Access Category | meaningful_access | meaningful_access |
| Outcome Category | strong_outcomes | strong_outcomes |
| Signals | - | Boarding and day school; 75% boarding and 25% day; No AP courses; most rigorous courses are designated Advanced; Only two Honors courses are offered: Honors Algebra II and Honors Precalculus; Students have limited opportunities to pursue Advanced-level courses before V Form; 34% of students receive financial aid; Average financial aid award reported as $58,375 for boarding students and $35,695 for day students; College Counseling Office includes a Director, Associate Director, Assistant Director, Counselor, and Registrar; 24% international students; Over the past three years, students chose more than 100 colleges and universities; Each year, on average, students matriculate at 60 different schools in more than 20 states, as well as countries outside the US; Virtually all graduates enroll in a four-year institution immediately upon graduation |