Which is bigger, a megabyte or a gigabyte? Quick Answer. A gigabyte (GB) is 1,000 times larger than a megabyte (MB), which is 1 million bytes. A GB of data storage can store approximately 1 billion bytes. One minute of an MP3 audio file is about 1 MB, while the size of a DVD movie is roughly between 4 to 8 GB. Continue Reading.