Zettabytes to Kilobytes (ZB to kB)

1 zettabyte equals 1×10¹⁸ kilobytes exactly.

1 zettabyte = 1×10¹⁸ kilobytes

How to convert zettabytes to kilobytes

To convert zettabytes to kilobytes, multiply the number of zettabytes by 1×10¹⁸. This factor is exact. To go the other way, multiply kilobytes by 1×10⁻¹⁸.

kilobytes = zettabytes × 1×10¹⁸

Example: 10 zettabytes = 1×10¹⁹ kilobytes.

Decimal prefixes (kB, MB, GB) are powers of 1,000; binary prefixes (KiB, MiB, GiB) are powers of 1,024. Storage makers use decimal; Windows reports binary but labels it GB.

About these units

Zettabyte (ZB)

ComputingCurrent unit

10²¹ bytes. Used for estimates of global data volumes.

Global data volumes are now large enough that the zettabyte, 10^21 bytes, has become a headline unit. It is decimal: 1,000 exabytes, or a trillion gigabytes, and the symbol is ZB. The prefix zetta was added to the SI in 1991 alongside yotta, and the binary counterpart is the zebibyte (ZiB), 2^70 bytes, which is about 18 percent larger.

Wikipedia's article on the Zettabyte Era puts the point when total digital data first passed one zettabyte at 2012. It also records Cisco's estimate that global IP network traffic first topped one zettabyte in 2016, at about 1.2 ZB, or roughly 96 exabytes a month. IDC forecasts quoted there projected annual data generation reaching 175 ZB by 2025, though such figures are estimates of data created rather than data kept, and they vary between analysts.

Almost nothing is stored in single zettabyte devices, so the unit matters mainly for industry totals.

1 zettabyte = 1×10²¹ bytes (exactly).

Sources: Wikipedia: Zettabyte Era; Wikipedia: Metric prefix; Wikipedia: Byte

Kilobyte (kB)

ComputingCurrent unit

1,000 bytes in the SI (decimal) definition. Older software and Windows sometimes use KB to mean 1,024 bytes; see kibibyte.

Few units have had two meanings for so long. By the mid-1960s most computers used binary addressing, so memory sizes came in powers of two and engineers borrowed kilo to mean 1,024. IBM documentation for the System/360 in 1964 used an uppercase K for 1,024. Hard disk makers took a different path from the start. The IEC later settled the question: kilobyte, symbol kB, means 1,000 bytes, and 1,024 bytes is a kibibyte.

Floppy disks show the muddle. The Shugart SA-400 of 1976 held 109,375 bytes unformatted and was advertised as 110 Kbyte, the decimal way, while a 1978 Tandon double-density disk held 368,640 bytes, or 360 times 1,024, and was sold as 360 KB. Windows still divides by 1,024, so a 65,536-byte file appears as 64 KB there, while Mac OS X Snow Leopard and later would call it 66 kB. A kilobyte is also tiny: Edgar Allan Poe's The Cask of Amontillado is 12,843 bytes.

1 kilobyte = 1,000 bytes (exactly).

Sources: Wikipedia: Kilobyte; Wikipedia: Binary prefix; NIST: Prefixes for binary multiples

Related conversions

See all digital storage units.