Which has smaller classes for undergraduates: Johns Hopkins or Amherst?

Amherst is more likely to provide the consistently small, discussion-centered undergraduate experience you describe. Its liberal arts college model is built around a much smaller undergraduate population, close faculty access, and classes that often emphasize seminar-style conversation rather than large lecture formats. At Johns Hopkins, many upper-level classes and major-specific courses are also small, but introductory courses can be noticeably larger.

Amherst students tend to encounter professors as their primary instructors from the start, including in first-year courses, and the campus culture makes it easier for faculty to know students across classes, advising, and campus life. The open curriculum can also help you move quickly into smaller courses in subjects you genuinely want to study.

Johns Hopkins fits students who want a research-university environment with strong access to labs, specialized departments, and a larger range of advanced offerings. You can still build close professor relationships there, especially through research, office hours, and upper-level work, but you should expect some larger foundational classes, particularly in popular STEM fields.

For someone placing small classes and regular interactive discussion near the top of the decision, Amherst offers the more reliably intimate academic setting.