Gigabyte is a unit of computer storage capacity. It is a multiple of the unit byte. One gigabyte equals roughly a billion bytes, or more specifically it has two definitions, the binary definition - 1073741824 bytes and the decimal definition of 1000000000 bytes. You can convert Gigabytes to other units here by enter amount of if into green input below. You can also check some basic conversions in Gigabytes Conversion Table.