Kilobytes, Megabytes and Gigabytes - Network Data Rates

A kilobyte equals 1024 (or 2^10) bytes. Likewise, a megabyte (MB) equals 1024 KB or 2^20 bytes and a gigabyte (GB) equals 1024 MB or 2^30 bytes.

The meaning of the words kilobyte, megabyte, and gigabyte change when they are used in the context of network data rates. A rate of one kilobyte per second (KBps) equals 1000 (not 1024) bytes per second. One megabyte per second (MBps) equals one million (10^6, not 2^20) bytes per second.

One gigabyte per second (GBps) equals one billion (10^9, not 2^30) bytes per second.

To avoid some of this confusion, networking professionals typically measure data rates in bits per second (bps) rather than bytes per second (Bps) and use the terms kilobyte, megabyte, and gigabyte only when referring to data size (of files or disks).

Examples

The amount of free disk space on a Windows PC is shown in units of MB (sometimes called " megs") or GB (sometimes called "gigs" - see screenshot).

The size of a file download from a Web server is likewise shown in units of KB or MB - large videos may also be shown in GB).

The rated speed of a Wi-Fi network connection is shown in units of Mbps.

The rated speed of a Gigabit Ethernet connection is shown as 1 Gbps.