Updated: 09/12/2023 by Computer Hope

M may refer to any of the following:

1. M is an abbreviation used for the MUMPS programming language.

2. When describing a keyboard shortcut or sequence, "M-" is the GNU (GNU's Not Unix) notation used to represent the meta key or Alt key if set up as a meta key. For example, M-c is short for pressing Alt and C at the same time on the keyboard. If the Alt key is not set up as a meta key, press the Esc and C to perform the shortcut.

3. M is a keyboard key used with the keyboard shortcuts Alt+M, Command+M, and Ctrl+M.

4. The letter "m" is also chat slang for "am."

5. With the ESRB (Entertainment Software Rating Board), an "M" rating is short for "mature" and is a game meant for players over the age of 17.

6. With regular expressions, "m" is a regular expression flag to allow for a multi-line match.

7. With Microsoft Excel and other spreadsheet programs, "M" is the thirteenth column of a spreadsheet. To reference the first cell in the column, you'd use "M1."

8. In Adobe Photoshop, M is a shortcut to select the Rectangular Marquee tool. Pressing Shift+M cycles through related tools, including the Elliptical Marquee tool.

9. With time notations, the lowercase m is for a minute. For example, with a long time, it may be formatted as "h:mm:ss tt," which is the same as "hour:minutes:seconds AM/PM."

10. With date notations, a capital M is used in the date format for the month. For example, with a long date, it may be formatted as "dddd, MMMM d, yyyy," which is the same as "day of week, month day, year."

11. With days of the week, M is an abbreviation for Monday.

12. M is the SI-derived symbol of mega, when using a lowercase m, it's a milli.

13. In the phonetic alphabet, "M" is often pronounced as "Mike."

14. As a Roman numeral, "M" is 1,000.

15. M is the thirteenth letter of the English alphabet. The letter "M" comes after "L" and is followed by the letter "N." To create a capitalized "M," press Shift and M at the same time.

On a U.S. QWERTY keyboard, the "M" key is on the bottom row, to the right of "N" and left of the "," (comma) key. See our keyboard page for a visual example of all keyboard keys.


If the "M" key is not working on the keyboard, see: Some keys on my computer keyboard aren't working.


In ASCII (American Standard Code for Information Interchange), the uppercase "M" is "077" in decimal (01001101 in binary). The lowercase "m" is "109" in decimal (01101101 in binary).


Doing the Alt code Alt+77 creates a capital "M," and Alt+109 creates a lowercase "m" character.


The number 6 on a phone keypad creates an "M" on a US phone.

Chat terms, Computer acronyms, Game terms, Letter, Programming language