About 11" on one side and 14" on the other, if I remember correctly. I usually side step as it is easier to manuver. To us it is well worth having the King size bed. You will get use to the space between the bed and the wall, especially in the middle of the night. We also installed a 3" memory foam mattress topper which really improved the comfort of the bed. We should have ordered the upgraded mattress, but was too cheap, I mean price conscience.
2013 Palomino Columbus 320RS
2007 Dodge RAM 2500 6.7 Cummins
Reese 15K manual slider
M.I.L. in Florida for good!!