Even if your bunny can stretch out it will not be "comfortable." The wire floor will be rough on it's feet and it won't have room to hop around significantly. Considering getting an exercise pen (30 or 36 inches should be plenty) in place of a cage. This will also make it easier to litter box train your rabbit (I use a large cat litter box, line it with newspaper and put hay on top of it). And still be sure to let your bunny out for exercise!