I think that it's definitely doable. Two of my good friends in college enrolled in a Kaplan class during our spring semester while both taking 16ish credits and being involved in other activities. From what I remember, they had classes twice a week (nights) for 2-3 hours at a time. Like what the other poster said, there's a lot of outside work to be done with these classes, and you should realize that attending class but doing minimal outside work would definitely be detrimental. That being said, I think it's perfectly doable, but expect your weeknights and all weekends to be full of work.