Mattress never made it past 9 inches along the edges. Inside the edges is more like 8 1/2. Gives mattress a concave appearance. I chose the 10 inch because that’s the size I currently had. They had thinner sizes at a cheaper price but I chose and paid for 10 inches. I don’t feel I received what I paid for. It sleeps pretty comfortable but is not anything out of ordinary there either. Wish I could say differently