I think it's about 8-9 ft. I have an 8'x16' rug and fit well. I placed it as close to edge of the bottom step and it provided plenty of room. The pics give a general idea. A 9'x12' mat would work well too, but I wanted the extra length.
TV: '15 Ram 6.4 Hemi CC 4x4
Old TT: '12 Rockwood Roo 19 (sold)
New TT: '14 CR Sunset Trail 290QB
WD: Equalizer 1200/12K
BC: Ram OEM