Caltech’s acceptance rate is 2.57% for the 2024-25 admissions cycle, making it one of the most selective universities in the United States. Out of every 100 students who apply, roughly two or three receive an offer of admission. That figure has dropped steadily over the past five years, falling from 6.69% in 2020-21 to its current level.
How the Rate Has Changed
Caltech’s selectivity has increased sharply in a short period. Here’s how the acceptance rate has trended over five recent admissions cycles:
- 2020-21: 6.69%
- 2021-22: 4.00%
- 2022-23: 2.69%
- 2023-24: 3.14%
- 2024-25: 2.57%
The biggest single-year drop came between 2020-21 and 2021-22, when the rate fell by nearly 2.7 percentage points. Since then it has hovered in the 2% to 3% range. Application volume has grown faster than the number of seats Caltech offers, which keeps the rate compressed. Caltech’s undergraduate enrollment is small by design, typically around 1,000 total students, so even modest increases in applications can push the percentage down noticeably.
Early Action vs. Regular Decision
Caltech offers Restrictive Early Action, meaning you can apply early but cannot simultaneously apply early to most other private institutions. The school states directly that its admit rate is under 5% for both Early Action and Regular Decision, and that the difference between the two is negligible. In practical terms, applying early does not give you a statistical advantage the way binding Early Decision programs can at some other schools. What it does give you is an earlier answer: you’ll know your status sooner, which can reduce stress and help you plan.
What Caltech Expects Academically
Caltech is, at its core, a science and engineering school, and the admissions requirements reflect that. Every first-year applicant needs to demonstrate mastery in a specific set of high school coursework designed to prepare them for Caltech’s rigorous core curriculum:
- Math: Four years, including one year of calculus
- Physics: One year
- Chemistry: One year
- Biology: One year (recommended but not strictly required)
- English: Four years
- History or social sciences: Two years minimum, with three or more recommended
The calculus, physics, and chemistry requirements are non-negotiable in most cases. If your school doesn’t offer one of those courses, or you have an unresolvable scheduling conflict, Caltech will accept alternatives: a score of 5 on the relevant AP exam, a 6 or 7 on the corresponding IB Higher or Standard Level exam, or completion of a course challenge through Schoolhouse.world. Both you and your school counselor need to document the reason the course wasn’t available.
Standardized Testing Requirements
Unlike many selective universities that made the SAT and ACT optional during and after the pandemic, Caltech requires first-year applicants to submit either the SAT or the ACT. There is no test-optional or test-free policy in place. If you’re applying to Caltech, plan to take one of these exams and submit your scores as part of your application. Caltech does not publish a median score range for admitted students, but given the sub-3% acceptance rate and the institution’s STEM focus, competitive applicants typically perform at the highest levels on quantitative sections.
Why the Rate Is So Low
Several factors combine to make Caltech’s acceptance rate unusually low, even among elite schools. The undergraduate class size is tiny. Each incoming class has roughly 235 to 250 students. That’s a fraction of what peer institutions like MIT or Stanford enroll. At the same time, Caltech’s reputation in physics, engineering, computer science, and related fields attracts a global applicant pool that has grown significantly in recent years.
The small class size also means Caltech doesn’t have room to accept students for dozens of different majors. Nearly every student will take the same demanding core curriculum in math, physics, chemistry, and biology during their first two years. Admissions readers are looking for students who are genuinely passionate about STEM and can handle that workload from day one. Strong grades and test scores are necessary but not sufficient. Research experience, competition results, and evidence of deep intellectual curiosity in science or math carry real weight.
What a 2.57% Rate Means for You
A rate this low means that even highly qualified students face long odds. Many applicants who are denied admission to Caltech go on to attend other top-tier universities. If Caltech is your first choice, treat your application as one piece of a broader strategy that includes schools where your chances are stronger. Focus your Caltech application on demonstrating genuine STEM depth rather than breadth across unrelated activities. The students who get in tend to show that science isn’t just something they’re good at but something they’ve pursued on their own, whether through independent projects, research mentorships, or competition participation.