Numbers in Morse Code

The ten digits

• 0 -----
• 1 .----
• 2 ..---
• 3 ...--
• 4 ....-
• 5 .....
• 6 -....
• 7 --...
• 8 ---..
• 9 ----.

Print this chart Fits on one sheet. Colors and navigation are left out automatically.

Every digit on its own

The lengths make a perfect V: 0 is the longest character in the code at 19 units, 5 the shortest digit at 9, and every step between them changes by exactly two. Each digit is also a letter with one or two elements added, which is the fastest way to learn them.

The pattern, and why it helps

Read the table downwards and the system appears. Each digit from 1 to 5 has as many dots as its value, followed by dashes to fill five places. From 6 onwards the count runs the other way: 6 has one dash, 7 has two, 8 has three, 9 has four, and 0 has five.

That symmetry is worth using. Rather than learning ten separate rhythms, learn the rule and count. Most people get the digits solid in an afternoon, while the letters take weeks - the letters have no system at all, because they were assigned by how often they appear in English text.

The cost of the system is length. Five signals for a single digit is slow, and a group like 1945 takes about as long to send as a short word. Operators therefore avoid sending numbers where they can, and where they cannot, they shorten them.

Shortened numbers on the air

In amateur radio, especially in contests where the same figures come up thousands of times, operators replace some digits with letters that sound similar but are shorter. These are called cut numbers.

• T for 0 - a single dash instead of five
• N for 9 - dash dot instead of four dashes and a dot
• A for 1 and E for 5 are also common

The classic case is the signal report 599, which almost everyone sends as 5NN. It saves eight signals every time, and in a contest that adds up to minutes. Outside that setting you should send digits in full: cut numbers only work when both operators expect them.