How big is the inside of a Dodge grand Caravan? In this video, I fold down the seats of a Dodge Caravan and measured the length width and height of the interior, so if you need to know how big the inside of a Dodge grand Caravan is, this video shows you all the measurements. The Dodge grand Caravan is big enough to fit a 4 x 8‘ sheet of plywood on the floor just barely. Watch this video if you want to know how big the inside of a Dodge grand Caravan is.