Bit rates | |||
---|---|---|---|
Name | Symbol | Multiple | |
bit per second | bit/s | 1 | 1 |
Decimal prefixes (SI) | |||
kilobit per second | kbit/s | 103 | 10001 |
megabit per second | Mbit/s | 106 | 10002 |
gigabit per second | Gbit/s | 109 | 10003 |
terabit per second | Tbit/s | 1012 | 10004 |
Binary prefixes (IEC 80000-13) | |||
kibibit per second | Kibit/s | 210 | 10241 |
mebibit per second | Mibit/s | 220 | 10242 |
gibibit per second | Gibit/s | 230 | 10243 |
tebibit per second | Tibit/s | 240 | 10244 |
In telecommunications, data transfer rate is the average number of bits (bitrate), characters or symbols (baudrate), or blocks per unit time passing between equipment in a data transmission system. Most commonly, measurements of data transfer rate are reported in multiples of unit bits per second (bit/s) or occasionally in bytes per second (B/s). The data rates of modern residential high-speed Internet connections are most commonly expressed in multiples of bits per second, such as megabits per second (Mbit/s) or kilobits per second (kbit/s).
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 bit/s, so that when a 1 Mbps connection is advertised, it usually means that the maximum achievable bandwidth is 1 Mbit/s (one million bits per second), which is 0.125 MB/s (megabyte per second), or about 0.1192 MiB/s (mebibyte per second). The Institute of Electrical and Electronics Engineers (IEEE) uses the symbol b for bit.
In both the SI and ISQ, the prefix k stands for kilo, meaning 1,000, while Ki is the symbol for the binary prefix kibi-, meaning 1,024. 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.