mega (M) (as a prefix to units of semiconductor storage capacity)

A multiplier equal to 1 048 576 (220 or K2, where K = 1024).

NOTE 1 Contrast with the SI prefix mega (M) equal to 106, as in a 1‑Mb/s data transfer rate, which is equal to 1 000 000 bits per second.

NOTE 2 The definitions of kilo, giga, and mega based on powers of two are included only to reflect common usage. IEEE/ASTM SI 10‑1997 states "This practice frequently leads to confusion and is deprecated." Further confusion results from the popular use of a "megabyte" consisting of 1 024 000 bytes to define the capacity of the familiar "1.44‑MB" diskette. An alternative system is found in Amendment 2 to IEC 60027‑2: Letter symbols to be used in electrical technology - Part 2:

Prefixes for binary multipliers
____________________________________________________________________
Factor Name Symbol Origin Derivation
210 kibi Ki kilo + binary: (210)1 = 1 024 kilo: (103)1
220 mebi Mi mega + binary: (210)2 = 1 048 576 mega: (103)2
230 gibi Gi giga + binary: (210)3 = 1 073 741 824 giga: (103)3
240 tebi Ti tera + binary: (210)4 = 1 099 511 627 776 tera: (103)4

IEC suggests that, in English, the first syllable of the name of the binary-multiplier prefix should be pronounced in the same way as the first syllable of the name of the corresponding SI prefix and that the second syllable should be pronounced as "bee".

References

JESD21-C#, 1/97
JESD100-B, 12/99

User login

Enter the password that accompanies your username.
Please note: passwords are now case-sensitive.

Browse Alphabetically

A | B | C | D | E | F | G | H | I | J | K | L | M | N | O | P | Q | R | S | T | U | V | W | X | Y | Z

Standards and Documents Assistance

Contact Julie Carlson, 703-624-9230

Dictionary RSS Feed

Subscribe to the JEDEC Dictionary RSS Feed to receive updates when new dictionary entries are added.