There are 1,048,576 bytes in a megabyte, and 1,0458,576 kilobytes in a gigabyte. This is one reason why your operating system will claim that there is less memory on your hard drive than what the manufacturer claims.ikewise, the standard definition for gigabyte is 1,000,000,000 (10^9) bytes. Dividing, this means there are 1,000,000 (1 million) kilobytes (kB) in a gigabyte (GB) .