1021 crewmen
so a deck is about 3 meters, so if you were to cut the ship into 3 meter wide sections, then you have it at about 350 3 meter sections.
seeing that each crewman needs about 15 meters of space to live, you get 29.695, multiply that by 35 and you get 1020.8333333333333333333333333333, not including families. Anyway the Galaxy class had about 350 civilians on board, and lets say the eclipse has 300, then you get about 721 as your answer.