People asked about mattress thickness and all the answers were any mattress up to 14 inches are comparable. However I can tell you it’s misleading. I got 10 inch mattress and it’s not bending. Head part will bend because  bed lifts up so mattress has to go in that direction but leg part stays in the air unless you put some weights on. On my pictures you can see that even head part does not bend unless I’m on a bed to put some weight. So my suggestion is get some thin mattress if you gonna buy this bed. This is my third review of products that I bought here and I’m not happy customer. All three products I bought at the same time so I wish I did not.