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).

Standards for unit symbols and prefixes

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 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.