Great futon mattress - it is a full 8" thick.  I had a nice looking futon mattress previously, but it was unbearable for my guests to sleep on.  Now I have a real mattress that offers much more comfort.  I read that some reviewers were unable to use it in the couch position because of the thickness, so I placed it in the couch position prior to allowing it to fully expand.  So far, no issues with that.  I would recommend to anyone in need of an inexpensive mattress or to upgrade a futon.