Just like the title says. Some places I have read that one pound of muscle burns as much as 50 calories a day. Somewhere else I read a pound of muscle burns 13 calories a day. And another place I read it only burns 6 calories a day! confusing! 
olympic weightlifters eat 8000+ calories daily, and bodybuilders more than that. They are not gaining any fat on them, and the both of them have a lot of muscle on them, so i would say that it's more than 10 calories. Otherwise they would be gaining more fat, so they would eat less than they do.
It only makes sense that it's a lot. My guess is under 50, and above 20 and the person who naturally has a high metabolism would be closer to 50, and vice versa.
agreed, lei.
Besides, proffessional olympic lifters train ALOT more than we do, they need the extra because their workouts burn alot of cals and speeds up their metabolism. Ive heard some of them works out like 9 times a week, so ofcource they need more food than the average joe.