I never really counted it up, but I'd guess about 4 hours a day plus 9 hours on Saturdays (because I work all day on Saturdays and I have nothing else to do at work but study). That's for five classes.
i thought i was gonna cut back until i read my first constitutional law case. The thing was like 15 pages - took an hour and a half to read/book brief and actually UNDERSTAND what the hell was going on for 15 pages. With con law im to about 4-5 hours a night. Without con law i would be doing an hour - 2 hours tops.