How do I manage my time?

There are 168 hours in a week, I wonder how I spend those hours throughout the course of the next week. How much time do I have free to myself? I started logging my time a week before last wednesday and over the course of that week I learned that I spent 16 hours in class, 13 hours at work, and roughly 15 hours on homework and studying. That leaves me with 120 hours of time that I have to my self. Sleeping probably takes up about 60 hours a week and the amount of time I work can fluxuate about 5 hours more or less. So I'm still left with about 60 hours of free time to eat, go out, and do whatever. I never noticed how much time I leave myself everyday, almost 9 hours each day I have nothing to do. With those hours, I'd like to say most of the time I am with my friends hanging out, or surfing the internet or watching TV. Seeing that I only spent 15 hours doing homework really bothers me. I got all my work done but its still half of what is expected by a college student. But I still dont imagine many students doing 30 hours of homework each week. Another factor that can effect my study time is that I dont have any required homework for my math class, so i spend way less time studying in that class than my others. In the future, I would like to spend a few more hours in my studies even if I completed my required work or dont have any required work. Procrastination is something I would like to avoid in college. I feel like I'm working harder than I ever did in highschool but I think i could spare a few more hours into my work.