Kilobit — unit of digital information (1,000 bits)

Characteristics

One kilobit = 1,000 bits. In terms of bytes (8 bits = 1 byte), 1 kilobit is 125 bytes (1,000 ÷ 8 ≈ 125). The kilobit is used as a decimal measure, so it scales by powers of ten: 1 megabit = 1,000 kilobits. For contrast, binary-based quantities use powers of two.

History and standards

The kilo- prefix comes from the International System of Units (SI). In computing the coexistence of decimal and binary scaling produced ambiguity. To reduce confusion, the International Electrotechnical Commission introduced binary prefixes (kibi-, mebi-, gibi-) to denote powers of two; for example the kibibit represents 1,024 bits. Official SI usage, however, keeps kilo as 1,000.

Uses and examples

• Data rates: kilobits per second (kbit/s or kb/s) is common for describing low-bandwidth connections and historical modem speeds.
• Small file sizes or signaling: some specifications and protocols report sizes in kilobits when decimal scaling is appropriate.
• Conversion example: 8 kilobits = 1,000 bytes (8 × 125).

Distinctions and common confusions

Kilobit is often confused with the kibibit, which equals 1,024 bits and arises from binary conventions. Notation matters: a lowercase b usually means bits, while an uppercase B denotes bytes (for example, kb vs kB). When precision matters—storage capacities, transfer rates, or technical specifications—check whether decimal (1,000) or binary (1,024) scaling is intended and consult technical documentation or standards like the SI guidance.