Zebibyte

A zebibyte (ZiB) is a unit of data storage equal to 2⁷⁰ bytes, or 1,180,591,620,717,411,303,424 bytes. Like kibibyte (KiB) and mebibyte (MiB), zebibyte has a binary prefix to remove any ambiguity when compared to the multiple possible definitions of a zettabyte.

A zebibyte is slightly larger than a zettabyte (ZB), which is 10²¹ bytes (one sextillion, or 1,000,000,000,000,000,000,000 bytes); a zebibyte is roughly 1.18 zettabytes. A zebibyte is 1,024 exbibytes, and 1,024 zebibytes make up a yobibyte.

Due to historical naming conventions in the computer industry, which used decimal (base 10) prefixes for binary (base 2) measurements, the common definition of a particular measurement could mean different numbers. When computer engineers first began using the term kilobyte to refer to a binary measurement of 2¹⁰ bytes (1,024 bytes), the difference between binary and decimal measurements was roughly 2%. As file sizes and storage capacities expanded, so did the difference between the two types of measurements — a zebibyte is roughly 18% larger than a zettabyte. Using different terms to refer to binary and decimal measurements helps to address the confusion.

NOTE: For a list of other units of measurement, view this Help Center article.