What is M in Morse code?

M is -- in International Morse—2 elements occupying 7 Paris timing units at standard ratios.

How do you say M aloud when learning?

Say it as dahdah (dits and dahs), not the words “dot” and “dash,” so your ear matches on-air copy.

What letter is -- in Morse code?

The pattern -- decodes to M; reversed, the same dots and dahs spell M (--).

What is M often confused with on copy?

Learners mix M with T (-) and O (---). Drill them back-to-back at one WPM before raising speed.

How long does M take at 20 WPM?

At 20 WPM one Paris unit is 60 ms, so M (7 units) lasts about 420 ms from the first dit or dah through the last element (letter space not included).

M in Morse Code

- -

Say it aloud: dahdah · NATO Mike · 7 timing units (~420 ms at 20 WPM)

By MorseCoder Team · Last updated: October 22, 2026

Quick answer

M is -- (dash-dash) with 2 elements. M in Morse code is -- (two dashes). Simple and memorable - two long signals.

At a glance: M

Spoken rhythm	Two dahs: dahdah.
Timing length	7 units (~420 ms).
English frequency rank	Rank 14; huge in abbreviations.
Mirror / reverse letter	Reverse: M (--).
NATO phonetic	Mike.
Koch lesson on MorseCoder	Lesson 1 introduces M with K.

Dot length at 20 WPM uses 1200÷WPM ms per unit — see Morse code timing & WPM.

Words starting with M

MUSIC -- ..- ... .. -.-.
MELON -- . .-.. --- -.
MARCH -- .- .-. -.-. ....
MIGHT -- .. --. .... -
MORAL -- --- .-. .- .-..

Timing for M

Mike is two three-unit dahs separated by one intra-character gap—seven units. A single long tone is T; M needs a visible dip between dahs at character speed.

Three worked examples with M

GM → --. --

M closes GM with two equal dahs—longer than T inside the word.
QRM → --.- .-. --

M ends QRM; hear dash-dash after R’s dit frame.
MM → -- --

Double M should sound like four dahs with one letter space between Ms.

Easy to confuse with T and O

Tango is one dah only. Oscar adds a third dah—listen for duration, not volume.

T (-)O (---)

Memory drill

"Mickey Mouse" (two humps). Lesson 1 Koch pairs M with K; compare lengths until T arrives in lesson 7. Tap thumb twice for the two dahs before adding other letters.

How M is used on the air

M anchors “GM,” “QRM,” “MM,” and names. Prefixes like MM or OM carry double-M rhythm. Because M is rank fourteen yet ubiquitous in abbreviations, nets feel M-heavy even when English statistics suggest otherwise. Skimmers decode M in callsigns under QSB; collapsing both dahs into one blob yields T in logs. Voice “Mike” follows when clarifying M-rich calls after CW. Morning regional nets open with GM after the ID; if the M is copied as T, the greeting becomes nonsense and the controller repeats the whole exchange, wasting time for everyone waiting.

Morse code timing diagram: a dot is 1 unit, a dash is 3 units, the gap between letters is 3 units and between words is 7 units

Sources

ITU-R M.1677-1 — International Morse timing and character set
ITU-R M.1172 — radiotelegraph abbreviations and operational signals
ARRL — Learning Morse Code
Our ITU-R M.1677-1 guide