If you are meaning how many megs does a game boy game take up if you backup the cartridge to a file, it will take up 4 to 16 megabytes depending on the game. Note that many times cartridges or flash memory are measured in megabits instead of megabytes, so if that is the case multiply by 8. 4MBytes would be 32mbits, 16MBytes would be 128mbits.
