mebibytes

A mebibyte (MiB) is a unit of digital information equal to 2^20 bytes, or 1,048,576 bytes. It is part of the binary prefixes introduced by the International Electrotechnical Commission (IEC) to distinguish binary multiples from decimal multiples. A mebibyte is also defined as 1024 kibibytes (KiB).

The mebibyte is distinct from the megabyte (MB), a term that has historically been used for both 10^6 bytes and, in some contexts, for 2^20 bytes. In practice, storage manufacturers often advertise sizes in decimal megabytes (MB), while memory sizes and software measurements may use binary prefixes. To reduce ambiguity, the IEC recommends using MiB for 2^20 bytes and MB for 10^6 bytes, though the latter usage remains common in some fields.

Usage and context: MiB is commonly encountered in computing memory, such as RAM and cache sizes, or in file sizes when precise binary counts are relevant. For example, 8 MiB equals 8,388,608 bytes. In bits, this is 67,108,864 bits. Some operating systems and tools display data capacities using the MiB unit, while others may show MB or use approximate decimal equivalents.

History: The binary prefixes (KiB, MiB, GiB, etc.) were standardized by the IEC in the late 1990s to reduce confusion with decimal prefixes. The term mebibyte combines the prefix mebi- with the byte unit.