noun
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A unit of computer memory or data storage capacity equal to 1,048,576 bytes (1,024 kilobytes or 2 20 bytes).
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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
Compare meaning
How does megabyte compare to similar and commonly confused words? Explore the most common comparisons:
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.
You can no longer think about things in terms of kilobytes or megabytes per second, because the amount of information is context-dependent.
From Salon
As the megabytes expended proved, you can make a compelling case for all and absolutely no guarantees about what follows.
From BBC
If you have photos to include with your response, please make sure they are larger than 1 megabyte in size and email them to [email protected].
From Seattle Times
A 48-megapixel file allows for photos with good detail even with significant cropping, but the file size of each photo can be 75 megabytes or larger.
From New York Times
The government adopted a new tax imposing levies on every phone call, text message and megabyte of data in March.
From Reuters
Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023
Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.