I built this bench to fit a foam matress that I had (kids are sleeping on it in my bedroom when they wake up at night).
The matress is 63 inches by 20 inches and the foam is 4 inched thick.
The bench is only 15 inches off the groung in height.
1 - 2x6
7 - 2x4
Miniwax Jacobean stain
rubbed on with a rag/cloth