Got this bed for my two boys. They love it. They recommended a 5 inch mattress for the bottom bunk, however, since it does not require a box spring i didn’t find that the 5 inch offered enough cushion for comfort. So we swapped it out for the 8 inch on the bottom as well as the same for the top bunk. Since our youngest is only 4 the height does not cause any issues and i don’t believe it will for some time.