kilobit

Kilobit is a unit of information equal to 1,000 bits in the decimal (SI) system. The common symbol is kb or kbit, and it is widely used to express data transfer rates as kilobits per second (kbps). In practice, kilobits are also encountered when referring to data sizes, but bytes are more commonly used for storage measurements.

One kilobit equals 125 bytes, since one byte consists of eight bits. This means that kilobit values must be converted to bytes when comparing with storage units such as kilobytes (KB). In data-rate contexts, kbps remains a decimal measure: 1 kbps equals 1,000 bits per second.

Ambiguity arises from historical usage: some older materials used kilobit to mean 1,024 bits. The precise binary equivalent is called a kibibit (symbol Kibit or KiBi depending on convention) and equals 1,024 bits. The kibibit is part of the broader effort to distinguish decimal prefixes (kilo, mega) from binary prefixes (kibi, mebi) in digital information.

Summary: kilobit is a decimal unit of information equal to 1,000 bits, commonly used in networking and data-rate expressions as kb or kbps. For binary sizing, 1,024 bits is properly a kibibit to avoid confusion with decimal kilobits.