A typical class at Harvard has 2,500 student admits. Of those, 700 are black or Hispanic. If Harvard did away with legacy admissions, 25 additional Hispanic or black applicants would be admitted, so 725. However, if they did away with affirmative action, 450 would not be admitted, so you would be down to 275. Most of these 425 spots would go to Asian applicants and a chunk would go to white applicants.

http://public.econ.duke.edu/~psarcidi/legacyathlete.pdf