What Does Zettabyte Mean?

A zettabyte (ZB) is a unit of digital information storage used to denote the size of data. It is equivalent to 1,024 exabytes or 1,000,000,000,000,000,000,000 bytes.


Techopedia Explains Zettabyte

The prefix "zetta" is part of the International System of Units (SI) and refers to 1021 units. Hard disk manufacturers label their products in SI, which may confuse some people in the IT field. The ISO, IEEE and the IEC all recommend using the unit zebibyte, which signifies 270 bytes and is more accurate for the measure of bytes.

Two interpretations can be made using the two standards:

Using SI, one zettabyte is equivalent to 1,000 exabytes or 1,000,000,000,000,000,000,000 or 1021 bytes.
Using traditional binary measurement, one zettabyte is equivalent to 1,180,591,620,717,411,303,424 bytes, that’s 270 bytes, also equivalent to 1 zebibyte (ZiB).


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Margaret Rouse
Technology Expert

Margaret is an award-winning technical writer and teacher known for her ability to explain complex technical subjects to a non-technical business audience. Over the past twenty years, her IT definitions have been published by Que in an encyclopedia of technology terms and cited in articles by the New York Times, Time Magazine, USA Today, ZDNet, PC Magazine, and Discovery Magazine. She joined Techopedia in 2011. Margaret's idea of a fun day is helping IT and business professionals learn to speak each other’s highly specialized languages.