OK let me clear this up. In common usage we say Kilobyte, Megabyte, gigabyte etc when we actually mean Kibi, mebi, gibibyte. So a kilobyte is 1000, mega 1000000 and giga 1000000000. However in common usage in computing we actually use the denary terminology for the binary values so they are taken to be the binary equivalets, ie 1024, 1048576 and 1073741824 respectively. I hope that clears up the confusion. To answer the question there are 1024 mega(mebi) bytes in a Giga(gibi)byte.