Mega-


Mega is a unit prefix in metric systems of units denoting a factor of one million. It has the unit symbol M. It was confirmed for use in the International System of Units in 1960. Mega comes from.

Common examples of usage

When units occur in exponentiation, such as in square and cubic forms, any multiples-prefix is considered part of the unit, and thus included in the exponentiation.
  • 1 Mm2 means one square megametre or the size of a square of by or, and not .
  • 1 Mm3 means one cubic megametre or the size of a cube of by by or 1018 m3, and not

    Computing

In some fields of computing, mega may sometimes denote information units, for example, a megabyte, a megaword, but denotes units of other quantities, for example, transfer rates: =.
In the case of 3½-inch floppy disks, sizes were given in megabytes of 1000KB or bytes.
The prefix mebi- has been suggested as a prefix for 220 to avoid ambiguity.