What Is Caltech's Acceptance Rate? 2026-27 Guide
TL;DR: Caltech's fall 2025 acceptance rate was 3.79% (428 admits from 11,285 applicants), and its yield was 57.94% (248 enrolled from 428 admitted), according to its 2025-26 Common Data Set. These are historical numbers, not a prediction for the fall 2027 cycle. Show readiness for a fast-moving STEM core, explain what you actually do when a problem gets difficult, and answer the current Caltech-specific prompts with concrete examples. If you want to pursue a STEM question further, the Lumiere Individual Research Program pairs you one-to-one with a mentor to shape and test an independent project.
If you're a high school student drawn to math and science and considering Caltech, you may be wondering what its acceptance rate means for you and how to show the work you love doing. This guide starts with the latest fully reported rates, then covers the courses and tests Caltech asks for, ways to describe your projects and activities, and the questions in its current supplement. You do not need to have a lab or a published paper to start building a thoughtful application.
What is Caltech's acceptance rate for the latest complete cohort?
The 2025-26 Common Data Set counts students who applied, were admitted and enrolled for fall 2025. Here is the matched arithmetic:
Fall 2025 | Count | Calculation |
Applicants | 11,285 | |
Admitted | 428 | 3.79% admit rate |
Enrolled | 248 | 57.94% yield |
The 3.79% rate uses the same fall 2025 class for both figures: 428 students admitted out of 11,285 who applied. Caltech also announced 428 offers for the later Class of 2030, but that announcement does not provide an acceptance rate for fall 2025. The fall 2027 cycle has no final rate yet.
Use the 3.79% rate to understand how selective Caltech has been, then focus on what you can show: your preparation in math and science, the work you pursued, and the choices you made when a problem got hard.
Does applying Restrictive Early Action change the Caltech math?
Caltech offers nonbinding Restrictive Early Action (REA) and Regular Decision. Its current admissions guidance says both rounds have admit rates under 5% and the difference is negligible. It reserves most offers for Regular Decision. The public guidance does not provide matched applicants and admit counts for each round, so an exact REA acceptance rate would be guesswork.
Caltech offers two application plans with different timelines:
Restrictive Early Action: Apply by November 1, 2026; send most other materials by November 6 and complete testing before November 30.
Regular Decision: Apply by January 4, 2027; send other materials by January 10 and complete testing before December 31, 2026.
REA limits other early applications, with stated exceptions. Read those rules before choosing a plan; a later, stronger application may serve you better than racing the early deadline.
What high school classes prepare you for Caltech?
Area | Caltech's stated first-year preparation |
Math | Four years, including calculus. |
Science | One year each of physics and chemistry; check the full course list. |
Biology | One year recommended. Biology broadens the science preparation Caltech recommends alongside its required physics and chemistry. |
English | Four years required. Use reading, writing and revision to explain scientific ideas clearly. |
History and social sciences | Two years required; three or more recommended. These courses help you examine evidence, context and the effects of technical choices on people. |
See Caltech's first-year academic requirements for the full list and its approved substitutions when a course is unavailable. SAT or ACT scores are required for fall 2027 applicants; Caltech reviews them in context and sets no minimum score.
Which extracurriculars can show scientific drive at Caltech?
Caltech reads what you pursued within the opportunities you had. You can show scientific drive through several kinds of work. For each, name a question or problem, the decision you made and what happened next:
A build or repair: Describe where a design failed and what you changed after testing it. The useful evidence is your process, not the price of equipment.
An investigation: Pick a question you can test, keep track of your method and explain what the results do and do not show. You can discuss what you discovered, what changed and what you would test next in your application. The Lumiere Individual Research Program pairs students one-to-one with a researcher mentor to develop an independent project from question to final paper.
A team or community contribution: Show how you helped others solve a technical problem, taught a concept or made a tool they used. Describe your own contribution. Research is one option among many, not a requirement.
Work beyond the classroom can give you concrete decisions, questions and findings to discuss in an application. Lumiere's admission results show college outcomes reported by former students in its programs.
What does Caltech's fall 2027 supplement ask about STEM curiosity?
Caltech's current supplement goes beyond a generic 'why us' answer. Its STEM-heavy prompts ask for:
STEM Academic Interest: In 150-200 words, name the area you chose and the problem or topic that draws you to it.
Scholarly Character: For one 200-word response, describe a moment of collaboration or uncertainty, what you tried and what another person contributed.
Scientific Drive: For two 200-word responses, take the reader through a question or something you built, tested, repaired or redesigned. Explain what you observed and would do next.
Community: In 100-150 words, say what you would share, make, teach or start with others at Caltech. Use the optional academic-context answer only when it adds useful context.
Check Caltech's live prompts before submitting because it updates them annually.
FAQs
Is 3.79% Caltech's rate for the Class of 2031?
No. It is the fall 2025 CDS rate from 428 admits and 11,285 applicants. The fall 2027 applicant pool has not finished its cycle, so it does not have a final rate.
How many students enrolled in the fall 2025 class?
The CDS records 248 first-year enrollees from 428 admitted students, for a 57.94% yield. Enrollment is different from offers of admission.
Does Caltech require published research?
Published research isn't required at Caltech, but a project can show how you think through a question. Explore a question you care about, then show what you tried and learned; that gives Caltech a concrete view of your curiosity and problem-solving. Lumiere's Individual Research Program pairs you with a mentor to pursue one. If you submit a paper, follow Caltech's optional research-material guidelines.
Can I write about a failed STEM project?
Yes. The current process prompt expressly asks how you worked through uncertainty and what you would defend about your approach, regardless of the outcome. Explain the specific choices rather than inventing a neat success story.