The smaller upper bunk is approx. 6ft by 2.8ft. The larger bunk above the wardrobe is 6ft by 3.7 ft. I don't have large kids so I built a crib front that connects to the walls over the top large bunk. My 18 month old son loves sleeping in the bunk it is his fort! I have laid in the larger bunk and it was comfortable, I haven't tried the small one. I can tell you my rectangular sleeping bag fits on it. My concern would be rolling off the bunk!
Phil, Michelle, Logan and Wyatt
2006 Dodge 2500 Heavy Duty 5.7 Hemi
2012 Rockwood 8312ss