Kbps is an acronym for kilobits per second, which is a measure of data transfer speed. One Kbps is equal to 1,000 bits per second. For example, a 300 Kbps connection can transfer 300,000 bits in one second. 1,000 Kbps is equal to 1 Mbps.
The term is a combination of kilo, a commonly used prefix with metric units of measurement to denote groups of 1,000, and bit, which is the smallest unit of information in a digital system. Note that while Kbps is 1,000 bits per second, a kilobyte (KB) is 1,024 bytes.
Kbps was used to measure the rate of data transmission in earlier technology, such as for dial-up modems. As recent innovations and improvements have led to faster speeds, data speeds are now measured with Mbps and even Gbps instead of Kbps. Systems using Mbps include broadband connections such as cable and DSL. Systems that still run at Kbps speeds include:
- 28.8K Modem: 28.8 Kbps
- 36.6K Modem: 36.6 Kbps
- 56K Modem: 56 Kbps
- Integrated Services Digital Network (ISDN): 128 Kbps
- Apple Desktop Bus (ADB): 256 Kbps
The lowercase “b” in Kbps is significant. Kbps should not be confused with KBps. Where the lowercase “b” in Kbps denotes bits, the uppercase “B” in KBps denotes byte, which is a group of eight bits. So, a kilobit would refer to 1,000 bits whereas a kilobyte would refer to 8,000 bits. Because data transfer speed is traditionally measured in bps, Kbps is more common than KBps.