In telecommunications and computing, bitrate (sometimes written bit rate, data rate or as a variable R or f_b) is the number of bits that are conveyed or processed per unit of time.

The bit rate is quantified using the bits per second (bit/s or bps) unit, often in conjunction with an SI prefix such as kilo- (kbit/s or kbps), mega- (Mbit/s or Mbps), giga- (Gbit/s or Gbps) or tera- (Tbit/s or Tbps). 1 kbit/s has almost always meant 1,000 bit/s, not 1,024 bit/s, also before 1999 when SI prefixes were defined for units of information in an IEC standard.

The formal abbreviation for "bits per second" is "bit/s" (not "bits/s"). In less formal contexts the abbreviations "b/s" or "bps" are often used, though this risks confusion with "bytes per second" ("B/s", "Bps").

Bit rates at various protocol layers