The R-21EC's cabin is approximately 190 cubic feet. That includes the volume of the cabinets and refrigerator.
The stand-up portion of the pilot house cabin measures 60" wide x 54" long x 74.5" high, so that space is approximately 140 cubic feet including the volume of the cabinets and refrigerator. The cuddy bed space is approximately 50 cubic feet. It is about 6'6" at its widest, 7' long, and 2' high, and has a raised ceiling over part of the bed which adds about 5 cubic feet.
If you need to be more precise for a/c calculations, for example, add another 3 cubic feet for the toilet space.
