Many Ivy League and other top-rated colleges accept only students with an "A" average (3.5 to 4.0 GPA). The average GPA for acceptance at Columbia University, for example, is 3.8. Schools also take other factors into account when reviewing applications for admission. Students with well-rounded experiences in high school tend to do better in colleges. The courses taken and extracurricular activities are considered.
The less competitive schools will sometimes choose students with a "B" average (2.6 to 3.4) or even lower. Depending upon your intended major and the requirements for the various departments, courses taken in high school may play a key role in the selection process. The math and science departments look for a transcript with higher grades in those subjects rather than just the overall average, especially if you intend to major in one of these subjects.
The majority of community and technical colleges are not as selective as four-year colleges, but usually require at least a 2.0 GPA, which is what students probably must have to graduate from high school. The two-year program can be a good place for some students to begin their college careers. Many community colleges offer remedial classes for students with low GPAs in math or English classes in high school.