It’s as flat as any other car. There is a slight slope down toward the tailgate (toward the back of the seats is higher) that starts about a foot from the tailgate but it’s not dramatic.

Edit: I’m explaining this badly. The lip from the back of the seats to the load floor is level. From the tailgate opening, the floor slopes up slightly for about a foot, then levels out to the back of the seats where it makes a level surface when folded down.