You can fit about 4 ½ cups of food into the Rover. Many people find that they can pack more food than they originally thought. This is because the lunchbox lid is raised so you can fill the tray up high.  If needed, the Big Dipper can be used independently of the Rover to store a snack outside of the main meal time.  The Big Dipper fits in the Carry Bag's snack pocket.