At Principia, your child's educational journey is guided by those who believe in boundless possibility.
Beyond a college-prep day and boarding school in St. Louis, Principia is founded upon Christian Science principles that see students as limitless and divinely whole.
Here, our students grow through character education and experiential learning to uncover natural strengths, critical thinking skills, and limitless potential.
Quick Facts (2025-26)
- Grades: (51³Ô¹ÏÍø Students) 8-12
- Grades: (Day Students) PK-12
- Enrollment: 500 students
- Yearly Tuition (51³Ô¹ÏÍø Students): $46,530
- Yearly Tuition (Day Students): $25,010
- Acceptance rate: 62%
- Average class size: 15 students
- Application Deadline: None / Rolling
- Source: Verified school update
Top Rankings
Principia School ranks among the top 20 boarding schools (out of 274 schools) for:
Category
Attribute
School Resources
School Overview
School Focus
College Preparatory
College Preparatory
Grades Offered (51³Ô¹ÏÍø)
8-12
9-12
Grades Offered (Day)
PK-12
6-12
School Type
Co-ed
Co-ed
Year Founded
1898
1907
Campus Size
360 acres
130 acres
First Day of School
Wed. Aug 12, 2026
Last Day of School
Thu. May 27, 2027
Student Body
Enrollment
500 students
320 students
% Students of Color
31%
27%
% International Students
17%
21%
% Students 51³Ô¹ÏÍø
28%
67%
Average SAT Score
1200
(Out of 1600)
(Out of 1600)
* National Avg. »
Average ACT score
29
(Out of 36)
(Out of 36)
*National Avg. »
Offers Post-Grad Year
No
No
Academics and Faculty
Saturday Classes
Yes
No
Frequency of Saturday Classes
Weekly
Less than once a month
Average Class Size
15 students
12
* National Avg. »
Student-Teacher Ratio
8:1
7:1
# of AP / Advanced Courses Offered
26
18
% Faculty with Advanced Degree
65%
73%
Summer Program Offered
No
Yes
Tuition Cost
Endowment Size
$590 million
$30 million
Yearly Tuition
(51³Ô¹ÏÍø Students)
(51³Ô¹ÏÍø Students)
$46,530
$68,856
Yearly Tuition
(Day Students)
(Day Students)
$25,010
$38,000
Tuition international students
$46,530
$58,650
% Students on Financial Aid
53%
39%
Avg. Financial Aid Grant
$17,000
$25,000
Admissions
SSAT Required
Yes
Yes
Acceptance Rate
62%
62%
Director of Admissions
Ginger Roth
Associate Director of Admissions
Jordan Poznick
Application URL
AP / Advanced Courses
# of AP / Advanced Courses Offered
26
18
Courses
Advanced Art DCAdvanced Ceramics DC
Calculus ABCalculus AB DC
Calculus BCCalculus BC DC
College Algebra DCCollege Chemistry DC
College Precalculus DCComputer Science A
Computer Science PrinciplesEnglish Language and Composition
English Language and Composition DCEnglish Literature and Composition
English Literature and Composition DCField and Natural History DC
Music TheoryPhysics
Physics 1 DCSpanish 4 DC
Spanish 5 DCSpanish Language
Statistics DCU.S. Government
U.S. Government DCU.S. History DC
Sports
# Interscholastic Sports Offered
13
16
Extracurriculars
Total Extracurricular Organizations
13
23
Extracurriculars
Club or Organization:
E-SportsMath Olympiad
Mediation TeamMock Trial
Poetry Out LoudRho Kappa Honor Society
Rotary ClubSpeech and Debate
Sustainability ClubTri-M
World Language Club
College Matriculation
College Acceptance Rate
96%
Year: 2022 - 2024
10 Most Popular College Choices (# Enrolled)
Principia College
42
School Notes
- Sample of notable school alumni/alumnae:
- Lewis Howes (US’01, C’05) - New York Times bestselling author of The School of Greatness
- Aaron Goldsmith (US’02, C’06)) - Broadcaster for the Seattle Mariners
- Robert Duvall (US’49, C’53) - Academy award winning actor
- Darcy Penick (US’96) - President of Bergdorf-Goodman
- Marika McCauley Sine (US’96) - Chief Sustainability Officer at Starbucks
- Kip Keller (US’19) - Professional soccer player - United Soccer League
- Candy Crowley (US’66) - American news anchor who was CNN's chief political correspondent, specializing in American national and state elections
- School Motto: As the sowing, the reaping
- School Mascot: Panther
Source: Verified school update
Frequently Asked Questions
How much does Principia School cost?
Principia School's tuition is approximately $46,530 for boarding students and $25,010 for day students.
What is the acceptance rate of Principia School?
The acceptance rate of Principia School is 62%, which is equal to the boarding school average of 62%.
Who are famous alumni from Principia School?
Principia School famous alumni include: Lewis Howes (US’01, C’05), Aaron Goldsmith (US’02, C’06)), Robert Duvall (US’49, C’53), Darcy Penick (US’96), Marika McCauley Sine (US’96), Kip Keller (US’19) and Candy Crowley (US’66).
What sports does Principia School offer?
Principia School offers 13 interscholastic sports: Baseball, Basketball, Cheering, Cross Country Running, Dance, Field Hockey, Football, Soccer, Swimming and Diving, Tennis, Track and Field, Volleyball and Wrestling.
What is Principia School's ranking?
Principia School ranks among the top 20 boarding schools for Large financial endowment.
When is the application deadline for Principia School?
The application deadline for Principia School is rolling (applications are reviewed as they are received year-round).
Nearby 51³Ô¹ÏÍø Schools
The nearest boarding school to Principia School is Chaminade College Preparatory School (3.7 miles away)
School
Location
Miles
Quick Facts
Chaminade College Preparatory School![Chaminade College Preparatory School Photo - Chaminade is located 20 minutes outside of Downtown St. Louis in the lovely, safe, green neighborhood of Creve Coeur. Our 55 acre campus is fun and lively throughout the school year and a wonderful place not only to study and play but also to become part of the family.]( "Chaminade College Preparatory School Photo - Chaminade is located 20 minutes outside of Downtown St. Louis in the lovely, safe, green neighborhood of Creve Coeur. Our 55 acre campus is fun and lively throughout the school year and a wonderful place not only to study and play but also to become part of the family.")
(Catholic)
425 South Lindbergh Blvd.
St. Louis, MO 63131
(314) 692-6645
St. Louis, MO 63131
(314) 692-6645
3.7 miles
Gr: 6-12 | 800 students Student-teacher ratio: 9:1 Avg. class size: 17 students Tuition listed
4100 South Lindbergh Blvd.
Saint Louis, MO 63127
(314) 843-4151
Saint Louis, MO 63127
(314) 843-4151
7.4 miles
Gr: 7-12 | 88 students Student-teacher ratio: 6:1 Avg. class size: 15 students Acceptance rate: 70% Tuition listed
204 Grand Street
Mexico, MO 65265
(573) 581-1776
Mexico, MO 65265
(573) 581-1776
84 miles
Gr: 7-12, PG | 220 students Student-teacher ratio: 11:1 Avg. class size: 14 students Acceptance rate: 65% Tuition listed
804 Dr Robert K Wallace Drive
Fairfield, IA 52556
(641) 472-9400
Fairfield, IA 52556
(641) 472-9400
183 miles
Gr: 9-12 | PK-12 (day) | 184 students Student-teacher ratio: 5:1 Avg. class size: 12 students Acceptance rate: 70% Tuition listed
Saint Bede Academy![Saint Bede Academy Photo - With an average student population of 300, our small class sizes offer students one-on-one interaction with their instructors.]( "Saint Bede Academy Photo - With an average student population of 300, our small class sizes offer students one-on-one interaction with their instructors.")
(Catholic)
24 W US Highway 6
Peru, IL 61354
(815) 250-0285
Peru, IL 61354
(815) 250-0285
200 miles
Gr: 9-12 | 293 students Student-teacher ratio: 12:1 Avg. class size: 18 students Acceptance rate: 80% Tuition listed
Recent Articles
Financing a 51³Ô¹ÏÍø School Education in 2025
Explore tuition trends, financial-aid strategies and payment options for boarding school families in 2025—making affordable access real.
51³Ô¹ÏÍø Schools & Phone/Social Media Policies 2025–26
Explore how boarding schools are updating cellphone and social media rules in 2025–26, with tuition, trends, and expert insight for parents and educators.
Corporal Punishment in U.S. 51³Ô¹ÏÍø Schools: 2025 Update
A current look at the use of corporal punishment in U.S. boarding schools, legal status, research findings and what parents should watch for in 2025.
