How does Carnegie Mellon compare to Cornell in acceptance difficulty for undergraduate admissions?

In general, both are very selective, but Cornell is usually a bit harder to get into overall by raw admit rate, while Carnegie Mellon can be just as hard or harder for certain majors.

For a broad comparison, Cornell gets a much larger applicant pool and rejects a higher percentage of applicants overall. Its Ivy League status and wide range of colleges draw huge numbers, which pushes the overall admit rate down. CMU is also extremely selective, but its selectivity is more uneven across programs.

The biggest practical difference is that CMU can be more difficult than Cornell in its most competitive divisions. The School of Computer Science at CMU is among the hardest undergraduate programs in the country to enter, and some arts programs are also exceptionally selective because admission depends on both academics and talent review. Cornell is also highly selective by college, with places like Engineering, Dyson, and certain majors in Arts and Sciences especially competitive, but its selectivity is usually discussed more at the university or college level than at the ultra-specialized program level.

So if you mean overall university-wide odds, Cornell is generally harder. If you mean specific top programs, especially CS or certain arts fields, Carnegie Mellon may be equally difficult or tougher. For building a realistic list, it makes sense to treat both as reaches for most applicants, then look closely at the exact school or major you would apply to.