The floor in my garage is 2x8 tongue and groove and far from flat. Those little 2" wheels on my Craftsman stool were always getting stuck. My knees and hips would hurt after a while from sitting so low. Well I finally fixed all that last night.
I added 5" swivel casters to make it roll better then added a 2x4 to raise it up just a little more. Seat is 12" wide and 16 1/2" high. Rolls great and as a added bonus it will clear my beer can so I don't have any accidental spills ;-)
A coat of walnut stain and clear urethane and it don't look to bad either.