megabyte
n.n. a unit of digital information that measures how much space a file takes up on a computer. One megabyte is roughly equal to one million characters of text.
n. a unit of digital information equal to 1,048,576 bytes in binary or exactly one million bytes in decimal contexts. Often used to quantify the size of small files like documents or low-resolution images.
The email attachment is only one megabyte in size.
The software update requires fifty megabytes of free space on your hard drive before it can begin the installation.
While modern high-definition video files are measured in gigabytes, a single megabyte remains a substantial amount of data for plain text documents or simple configuration files.
From mega- + byte.
Etymology adapted from Wiktionary, available under CC BY-SA 4.0.
Often abbreviated as MB; in common usage, it refers to the decimal million, though in technical computing it may refer to the binary power of two.
Last updated July 22, 2026