Unit symbol The
ISQ symbols for the bit and byte are
bit and
B, respectively. In the context of data-rate units, one byte consists of 8 bits, and is synonymous with the unit
octet. The abbreviation bps is often used to mean , so that when a connection is advertised, it usually means that the maximum achievable bandwidth is (one million bits per second), which is (
megabyte per second), or about (
mebibyte per second). The
Institute of Electrical and Electronics Engineers (IEEE) uses the symbol b for bit.
Unit prefixes In both the
SI and ISQ, the prefix k stands for
kilo, meaning 1000, while Ki is the symbol for the
binary prefix kibi-, meaning 1024. The binary prefixes were introduced in 1998 by the
International Electrotechnical Commission (IEC) and in
IEEE 1541-2002 which was reaffirmed on 27 March 2008. The letter K is often used as a non-standard abbreviation for 1,024, especially in "KB" to mean KiB, the
kilobyte in its binary sense. In the context of data rates, however, typically only decimal prefixes are used, and they have their standard SI interpretation.
Variations In 1999, the IEC published Amendment 2 to "
IEC 60027-2: Letter symbols to be used in electrical technology – Part 2: Telecommunications and electronics". This standard, approved in 1998, introduced the prefixes kibi-, mebi-, gibi-, tebi-, pebi-, and exbi- to be used in specifying binary multiples of a quantity. The name is derived from the first two letters of the original SI prefixes followed by bi (short for
binary). It also clarifies that the SI prefixes are used only to mean powers of 10 and never powers of 2. == Decimal multiples of bits ==