kibibyte

IPA/ˈkɪbibaɪt/
IPA/ˈkɪbibaɪt/

kibibyte — noun

  • kibibytesingular
  • kibibytesplural

1. A binary-based unit used to measure computer data or storage capacity, equal to

1.nounC1
Definition

A binary-based unit used to measure computer data or storage capacity, equal to 1,024 bytes (the 10th power of 2). Unlike the kilobyte (which is 1,000 bytes in decimal contexts), the kibibyte always uses powers of 2 and is the standard unit for reporting memory sizes and file-system blocks.

Example

Keiko downloaded a font file that was exactly 64 kibibytes in size.

The old cartridge stored 16 kibibytes of game code and save data.

contrast with kilobyte (KB = 1000 bytes) — KiB uses binary

Common collocations
  • kibibyte of data
  • kibibyte of memory
  • measured in kibibytes
  • per kibibyte
  • kibibyte boundary
  • kibibyte block
  • 64 kibibytes
  • 512 kibibytes
Synonyms
  • KiB

    the standard abbreviation; used in technical writing and system tools instead of the full word

Grammar Patterns

number + kibibyte(s) of + [data/memory/storage]

Usage Note

Kibibyte (KiB) and kilobyte (KB) are often confused. Kilobyte uses the decimal prefix 'kilo-' meaning 1,000; kibibyte uses the binary prefix 'kibi-' meaning 1,024. Many operating systems display file sizes in kibibytes but label them as 'KB'. Tools that follow the IEC standard show KiB when the value is computed in powers of 2.

Common Mistakes

A kibibyte equals 1,000 bytes.
A kibibyte equals 1,024 bytes (2¹⁰).
'Kibi-' stands for 'kilo-binary' and always uses powers of 2, not the decimal 1,000.

Word family

  • kibibit
    nounC2
  • mebibyte
    nounC2
  • gibibyte
    nounC2

Synonym discussion

Sense: noun/1

A kibibyte (KiB) is a binary unit equal to 1,024 bytes, while a kilobyte (KB) is a decimal unit equal to 1,000 bytes. The difference matters in computing because memory addresses and file-system blocks are naturally aligned to powers of 2. A mebibyte (MiB) is 1,024 KiB, making it the next step up in the IEC binary prefix system. A byte is the fundamental unit that all these larger units are built from. A kibibit (Kibit) measures 1,024 bits rather than bytes — one kibibyte equals 8 kibibits. In everyday use, many operating systems still display sizes in KiB but label them as KB, which causes the well-known discrepancy where a '500 GB' hard drive appears as roughly 465 GiB.

kilobyte ↗mebibytebyte ↗kibibit

Common collocations

Nouns

Phrases

  • measured in kibibytes
  • kibibyte boundary alignment
  • n kibibytes in size

Prepositions

Etymology

GreekEnglish blend (kilo- + binary)English

The word 'kibibyte' was adopted in 1998 by the International Electrotechnical Commission (IEC). 'Kibi' is a blend of 'kilo-' (from the Greek chilioi, meaning thousand) and 'binary' — forming a portmanteau that signals 'binary kilo'. The term was created to remove the ambiguity of 'kilobyte', which had been used for both 1,000 bytes (decimal) and 1,024 bytes (binary) in different contexts.