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megabyte

American  
[meg-uh-bahyt] / ˈmɛg əˌbaɪt /

noun

Computers.
  1. 2 20 (1,048,576) bytes.

  2. (loosely) one million bytes. MB


megabyte British  
/ ˈmɛɡəˌbaɪt /

noun

  1. Abbreviation: MB.   mbytecomputing 2 20 or 1 048 576 bytes See also mega-

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

megabyte Scientific  
/ mĕgə-bīt′ /
  1. A unit of computer memory or data storage capacity equal to 1,048,576 bytes (1,024 kilobytes or 2 20 bytes).

  2. One million bytes.


megabyte Cultural  
  1. A unit of computer information: one million bytes.


Usage

In computer science and industry usage, the prefix mega– often does not have its standard scientific meaning of 1,000,000, but refers instead to the power of two closest to 1,000,000, which is 220, or 1,048,576. The calculation of data storage capacity (measured in bytes) is based on powers of two because of the binary nature of bits (1 byte is 8, or 23, bits). Thus, a megabyte is 1,048,576 bytes, although it is also used less technically to refer to a million bytes. Other numerical prefixes are interpreted similarly. With data transmission rates (measured in bits per second), a bit is considered as a signal pulse, and calculations are generally based on powers of ten. Thus, a rate of one megabit per second is equal to one million bits per second. However, in certain technical contexts, megabit can also refer to 1,048,576 bits. Similarly, the prefix kilo– refers to 1,000 or 210 (1,024); giga– to 1,000,000,000 (one billion) or 230 (1,073,741,824); and tera– to 1,000,000,000,000 (one trillion) or 240 (1,099,511,627,776).

Etymology

Origin of megabyte

First recorded in 1965–70; mega- + byte

Compare meaning

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Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

In Hamilton, New Jersey State Police’s own TPPO-detecting dog, Mega - a nickname of his full name, Megabyte - bounded into the Digital Technology Investigations Unit.

From Washington Times • Feb. 24, 2018

This means estimating whether it will cost you more per Megabyte to transfer the information or to have it faxed to you by a friendly librarian.

From Email 101 by Goodwin, John