When I went to school in the dark ages it was 15 credits. I hear they have dumbed down college now, so it is 12 credits. Depending upon how many credits per class, that would be 3-4 classes per quarter or semester, but not all classes meet every day. Figure 3 hours of class per day. Colleges do not spoon feed you the information so you have to do a lot of study for each hour of class. 12 hours is considered to be full-time in college.