About Stony Brook University (SUNY). Stony Brook University (SUNY) in Stony Brook, NY reports an overall acceptance rate of 49.0%, an early-round acceptance rate of 70.5%, an SAT middle 50% of 1340–1480, a class size of 4,042, and a yield of 17.0% based on the most recent Common Data Set filings. Top SUNY research university and AAU member. Strong STEM programs, especially in physics and computer science. Test-optional with 49% acceptance rate.