Every digit is exactly five signals, and the whole table follows from one rule — no memorising. Plus the cut numbers radio amateurs use: why “5NN” means 599.
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02
The five-signal rule
1 to 5dots first, dashes fill up to five
1·−−−−i-TOOL-KOO-OO-DNAA
2··−−−dve-ne-KHOO-ROO-SHOO
3···−−tri-te-be-MAA-LOO
4····−che-tve-ri-te-KAA
5·····pya-ti-le-ti-e
6 to 0dashes first — the digit minus five
6−····POO-shes-ti-be-ri
7−−···DAA-DAA-se-me-ri
8−−−··VOO-SMOO-GOO-i-di
9−−−−·NOO-NAA-NOO-NAA-mi
0−−−−−NOOL-TOO-OO-KOO-LOO
For 1 to 5, the digit is the number of leading dots. For 6 to 0, the number of leading dashes is the digit minus five.
03
Cut numbers
how digits are shortened on air
599→5NN
5
readability
9 → N
strength
9 → N
tone
An RST report of “599” is a perfect signal. On air the nine −−−−· is replaced by the letter N −·: half as long, and clear from context.
Digit
Full
Cut
1
·−−−−
·− (A)
rarer
2
··−−−
··− (U)
rarer
3
···−−
···− (V)
rarer
4
····−
—
none
5
·····
· (E)
rarer
6
−····
—
none
7
−−···
−··· (B)
rarer
8
−−−··
−·· (D)
rarer
9
−−−−·
−· (N)
common
0
−−−−−
− (T)
common
04
About the numbers
Numbers in Morse code are stricter than letters: each is exactly five signals long, and the order of dots and dashes follows a single rule. Know the rule and you don't need the table. On air, radio amateurs also shorten long digits — faster, but hard to read without knowing the convention.
Five signals
Rule
1 = ·−−−−
Every digit is five elements. Its length alone tells it apart from a Latin letter.
1 to 5
Dots first
3 = ···−−
As many dots at the start as the digit. Dashes fill the rest.
6 to 0
Dashes first
7 = −−···
As many leading dashes as the digit minus five. Zero is five dashes.
Cut numbers
On air
0 → −
Long digits are replaced by a short letter: zero by T, nine by N. Other cuts are less common.
5NN
Signal report
599 = 5NN
The report “readability 5, strength 9, tone 9” goes out as 5NN — the nines replaced by N.
Chants
Mnemonic
dve-ne-KHOO-ROO-SHOO
Russian operators learn digits with five-syllable chants, too; the long syllables sound like dashes.
05
Frequently asked questions
Each digit is five signals. From 1 to 5 the digit starts with that many dots and dashes fill the rest: 3 = ···−−. From 6 to 0 it is the other way round: the digit minus five gives the number of leading dashes, and dots fill the rest: 7 = −−···, 0 = −−−−−. A number is sent digit by digit, with a letter-length pause between digits.
So they can't be confused with letters: the longest Latin letters are four signals, while digits are always five. And one rule covers them all, so you can work out any digit without a table: from one to five the number of leading dots grows, from six to zero the number of leading dashes. The price is length, which is why radio amateurs shorten them.
Radio amateurs replace long digits with short letters to send faster: most often 0 becomes T (−) and 9 becomes N (−·). Less often the others are cut too: 1 as A, 2 as U, 3 as V, 5 as E, 7 as B, 8 as D. Such a recording can only be read from context, in signal reports for example. The translator above has a Cut switch.
It is 599, a signal report on the RST scale: readability 5 out of 5, strength 9 out of 9, tone 9 out of 9. The nines go out cut, as the letter N: −· instead of −−−−·, half as long. The report is sent in almost every short contact and in contests, which is why “5NN” is one of the most recognisable groups on the air.
Digit by digit, with a pause between digits as between letters. Brackets and hyphens can be dropped, and a date can be split with the slash sign −··−·. Better not to use cut numbers in phone numbers: the recipient may not know the convention, and one wrong digit makes the number useless. Type the number into the translator above to see the code and hear it.
The five-signal rule is the mnemonic. From 1 to 5, count the leading dots; from 6 to 0, the leading dashes equal the digit minus five, so 7 starts with two dashes. Fill the rest of the five places with the other signal. Russian operators also learn digits with five-syllable chants, such as “dve-ne-KHOO-ROO-SHOO” for 2, but the rule gets you there faster.