The Morse Code Alphabet Explained
Every letter from A to Z in International Morse code, the timing rules that hold it together, and why the most common letters have the shortest codes.
The Morse code alphabet is a set of 26 short patterns of dots and dashes, one for each letter, that can be sent as sound, light, or electrical pulses. It has survived for nearly two centuries because it is extraordinarily simple to transmit and surprisingly easy to learn once you understand the logic behind it. This article gives you the full table, explains the timing rules that make it readable, and shows why the alphabet is shaped the way it is.
A quick bit of history
Samuel Morse and his collaborator Alfred Vail developed the original code for their electric telegraph in the 1830s and 1840s. That version, now called American Morse, used dots, dashes and several different lengths of space. In 1848 Friedrich Clemens Gerke simplified it for use on German railways, and his version, with only two element lengths, became the basis for International Morse code, standardised in 1865 by what is now the International Telecommunication Union. International Morse is the one used worldwide today, and it is the one in the table below.
The full A to Z table
| Letter | Code | Letter | Code |
|---|---|---|---|
| A | .- | N | -. |
| B | -... | O | --- |
| C | -.-. | P | .--. |
| D | -.. | Q | --.- |
| E | . | R | .-. |
| F | ..-. | S | ... |
| G | --. | T | - |
| H | .... | U | ..- |
| I | .. | V | ...- |
| J | .--- | W | .-- |
| K | -.- | X | -..- |
| L | .-.. | Y | -.-- |
| M | -- | Z | --.. |
You can see the same chart with audio playback for every letter on our Morse code alphabet page, or type any word into the translator to hear it sent.
The five timing rules
A list of dots and dashes is only half the story. What makes Morse intelligible is timing. Everything is measured against the length of a single dot, called one unit:
| Element | Length |
|---|---|
| Dot (dit) | 1 unit |
| Dash (dah) | 3 units |
| Gap between elements within a character | 1 unit (silence) |
| Gap between letters | 3 units (silence) |
| Gap between words | 7 units (silence) |
These ratios are what let a listener tell the difference between, say, the letters E-T (dit, pause, dah) and the single letter A (di-dah). In the first case there is a three-unit silence between the elements; in the second there is only one. Get the gaps wrong and even perfectly formed dots and dashes become unreadable. This is why experienced operators care far more about spacing than about speed.
What “words per minute” actually means
Speed in Morse is quoted in words per minute, but words vary in length, so the standard uses a reference word. The word PARIS, including the gap that follows it, is exactly 50 units long, and its letter mix is close to average English. So 20 WPM means the word PARIS could be sent twenty times in one minute, which works out to a dot length of 60 milliseconds. At 5 WPM a dot is 240 milliseconds. Some software uses CODEX, a 60-unit word, as an alternative reference for random-group practice.
Why E is a single dot
The alphabet is not arbitrary. The most frequently used letters in English were given the shortest codes, which keeps messages short and operators less tired. The story usually told is that Alfred Vail visited a local newspaper and counted the pieces of type in the compositor’s cases: the letters with the most type were the ones printers used most. Whether or not it happened exactly that way, the result is clear:
- E, the most common letter in English, is a single dot.
- T, the second most common, is a single dash.
- I, A, N and M, all frequent, use two elements.
- Rare letters like Q, J, Y and Z use four elements, often with several dashes.
An average English sentence in Morse is therefore much shorter than it would be if the codes were assigned alphabetically. It is an early, intuitive form of what information theorists later formalised as variable-length coding.
Hearing patterns, not counting symbols
The table above is useful for reference, but it is not how anyone actually learns Morse. If you try to memorise the chart visually, you will find yourself counting elements and translating in your head, which caps your speed around five to ten words per minute. Fluent operators hear each letter as a rhythm: C is “dah-di-dah-dit”, a little gallop; O is three long “dah-dah-dah”; S is three quick “di-di-dit”.
Several letters are mirror images of one another, which is worth knowing even if you learn by ear. A (di-dah) reverses to N (dah-dit). D (dah-di-dit) reverses to U (di-di-dah). B (dah-di-di-dit) reverses to V (di-di-di-dah). G (dah-dah-dit) reverses to W (di-dah-dah). Beginners sometimes confuse these pairs, which is one reason good courses introduce them at different times rather than side by side.
Letters with accents and other alphabets
International Morse defines codes only for the basic Latin alphabet, the digits, and a set of punctuation marks. Many languages have added non-standard extensions: Ä is often sent as .-.-, Ö as ---., Ü as ..--, and Ñ as --.--. These are widely understood but not part of the ITU standard. Entirely separate Morse tables exist for Cyrillic, Greek, Hebrew, Arabic and Japanese, each mapping local characters onto the same dot-and-dash patterns where possible.
Beyond the letters
Once you are comfortable with A through Z, you will want the digits and the handful of punctuation marks that appear in real traffic. The numbers follow a beautifully regular pattern that you can learn in a single sitting, and a few special combined characters called prosigns handle things like “end of message”. We cover all of them in Morse code numbers, punctuation and prosigns. And of course, the one three-letter sequence everyone should know is covered in our article on SOS.
Bookmark the table, but do not study it. Put on headphones, play a couple of letters at full speed, and let the rhythms do the work. That is how the alphabet actually goes in.
