5 hours usually. and to compensate for lost hours, I sleep in classes. in fact, my latin teach created a new classroom rule in my honor: no sleeping in class or get a detention. unfortunately, I was the first (and only so far) to be an example of that rule.
I get about 6 per day, and it's not enough. I'd say 8.5-9 would be ideal, but whenever I don't get that much (read: between September and June, on weekdays), naps on the subway and sleeping late on the weekends compensate.
I try to average 6 during the week, 8 on the weekends if I'm lucky. I'd like to get more, but I'm just a night owl. Of course in college it was much much less hehehe, but I'm older and much more mature now well sorta.
I swear on nights I get only 4-6 hours of sleep I feel significantly more refreshed and ready for the day in the morning then the nights I get 7+. I'm certainly not the only one who feels this way, does anyone know anything scientific regarding this?