kilobyte [kB] Unit Converter

Definition of kilobyte [kB] unit

A kilobyte (kB) is a unit of digital information equal to 1,000 bytes under the International System of Units. In computing, “KB” has also traditionally denoted 1,024 bytes, though kibibyte (KiB) is the precise binary term.

History of kilobyte [kB] unit

The word kilobyte emerged during the early computer era, when memory and storage capacities were measured in powers of two. Because 2^10 equals 1,024, engineers commonly used kilobyte to mean 1,024 bytes, despite the metric prefix kilo meaning 1,000. As storage became larger and international standards more important, the International Electrotechnical Commission introduced kibibyte (KiB) in 1998 for 1,024 bytes, while kilobyte (kB) retained its decimal meaning. Both usages remain visible, creating occasional confusion in software documentation, operating systems, and product marketing.

Applications of kilobyte [kB] unit

Kilobytes are used to describe small digital files and data quantities. A plain-text document, short email, or simple webpage may occupy several kilobytes. File systems and download meters report sizes in KB or kB, while programmers use byte-based measurements for buffers and records. Kilobytes also appear when comparing documents, images, configuration files, and network transfers alongside megabytes and gigabytes.

Complete list of kilobyte [kB] unit conversion