A lot of factors influence your ultimate college decision, and an important one to consider is college size. You need to make sure that you're comfortable with the size of your college and that it will be able to meet all of your needs. Here's a quick breakdown about what small, medium, and large colleges will be able to offer you.
To be considered small, a college will usually have fewer than 5,000 undergraduate students total. This means everything about the college will be smaller: the campus, the faculty, and the number of people in each class. A smaller college will usually be quieter, and you'll become more familiar with the other students and faculty in a shorter amount of time. However, the smaller the college, the fewer available majors and areas of study there will be, and schools with highly specialized areas of study tend to be smaller (such as the Pratt Institute in New York, which has just over 4600 students and specializes in design).
A medium-sized school, which has more than 5,000 undergraduate students but less than 15,000, shares some qualities with both small and large universities. The campus is larger, which means some of your classes will be too, and you'll have opportunities to meet more people. Larger colleges also offer a wider variety of extracurricular activities, so you're more likely to find student clubs that match your hobbies and interests. In addition, there are usually more majors and degree plans offered at larger schools.
Large colleges have undergraduate populations of over 15,000 students. The campuses will be expansive, which means it could take longer to walk to class than it would at a smaller school. Large colleges have multitudes of athletic and extracurricular opportunities. Because of all the extracurricular groups on campus, you'll still be able to find people with similar interests among the thousands of other students. You won't have to worry about not finding your major at a large university, but most of your classes will be auditorium-style, instead of classroom-style.