You need approximately 33 to 36 inches between the top of the mattress and the ceiling. Most ceilings are 8 feet high, which means you need an extra 4 or 5 inches. You can fit a loft bed in a room with an 8-foot ceiling if you use a thinner mattress. ;You can also opt for a half loft bed, which isn’t as tall as a standard loft bed. It doesn’t provide enough space beneath it for other furniture, but it can usually accommodate extra storage room.;