How do Stanford and Caltech compare in undergraduate class sizes?

Caltech is the more consistently small-class environment for an undergraduate who wants close contact with faculty and a very small peer cohort. Stanford has a far larger undergraduate population, so class sizes vary much more by course level and department.

At Stanford, many seminars, humanities courses, and upper-level engineering or physics electives are small, often making it possible to know professors well. But introductory STEM lectures and popular computer science or engineering courses can enroll dozens or hundreds of students; the smaller experience may come through discussion sections, labs, office hours, or research groups rather than the main lecture itself.

Caltech’s required Core Curriculum means first-years take many demanding math and science courses with the same relatively small group of classmates. Some core lectures can still be sizable in relation to Caltech’s class year, but they are rarely comparable to Stanford’s largest gateway courses. The academic culture also tends to make collaboration, faculty access, and shared problem sets central parts of daily life.

For a student who wants engineering or physics within a broad university, with abundant course choices and the option to move between large lectures and intimate seminars, Stanford can provide both settings. For someone who wants the small-scale setting to be the default, especially in a tightly focused science-and-engineering community, Caltech is likely to feel noticeably more personal from the start.