What does kilobit mean?
A kilobit is a unit of digital information equivalent conventionally to 1,024 bits, though strict SI usage defines one kilobit as 1,000 bits. The word is especially common when describing the speed of a data connection, as in '56 kilobits per second,' and can also refer to the amount of information stored in a digital file or message. A kilobit must not be confused with a kilobyte: a byte consists of eight bits, so a kilobyte represents roughly 8,192 bits under the traditional 1,024-byte convention. The term is now most often encountered in discussions of internet performance, data allowances, and telecommunications, although it was once especially associated with dial-up modems. The symbol 'kbit' is preferred in technical writing when the unit must be distinguished from a kilobyte.
nounA unit of digital information equal to 1,024 bits, although in contexts governed by the International System of Units, a kilobit is sometimes taken to mean 1,000 bits. It is commonly used in describing data transmission rates and storage or memory capacities.
- A unit of digital information conventionally equal to 1,024 bits; under strict SI usage, 1 kilobit may instead equal exactly 1,000 bits.
"The early modem transmitted data at a rate of 56 kilobits per second."
"The connection speed was measured in hundreds of kilobits per second."
"The file contains a few thousand kilobits of text."
The plural is used when referring to multiple units or to a rate expressed in kilobits per second.
"The old connection was limited to 56 kilobits per second."
A kilobit is tiny by modern standards, but the one million bits in a megabit help explain why a modest download can still consume a noticeable amount of mobile data.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Where does kilobit come from?
The word combines the prefix kilo-, derived from the Greek 'chiliad' meaning 'a thousand,' with bit, a digital unit ultimately associated with binary information and digital computing. Although 'kilo' normally denotes a factor of 1,000 in the International System of Units, historical computing usage commonly treats a kilobit as 1,024 bits because 1,024 is a power of two. Modern technical contexts therefore distinguish the traditional binary convention from the SI definition of exactly 1,000 bits.
How kilobit is actually used
The abbreviation is commonly written 'kbit' or 'kb', although 'kb' is sometimes used loosely for kilobytes. When precision matters, writers should state whether the convention is 1,000 or 1,024 bits and distinguish bits from bytes.
Easily confused with kilobit
A kilobit is a unit of information equal to 1,024 bits, while a kilobyte contains eight times as many bits.