CIPHERNAUT
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Cipher catalogue
EncodingDifficulty: Easy

Letter numbers (A1Z26)

Swap every letter for its place in the alphabet: A is 1, B is 2, and so on. Roman numerals work too.

Try it

27 characters

Result · Letter numbers (A1Z26)

19 5 3 18 5 20 / 13 5 19 19 1 7 5 / 6 15 18 / 20 8 5 / 3 12 21 2

How it works

  1. 1Write out the alphabet and number it: A is 1, B is 2, C is 3 … Z is 26.
  2. 2Replace each letter of your message with its number. MAKOSO becomes 13 1 11 15 19 15.
  3. 3Separate the numbers with a space, semicolon, dash or dot. Words are split with a slash.
  4. 4Want it trickier? Write the numbers as Roman numerals (13 is XIII).
  5. 5To decode, go backwards: for each number, find the letter at that spot in the alphabet.

Example

SECRET

19 5 3 18 5 20

Did you know

Numbering letters is one of the simplest ciphers and turns up in puzzle hunts and scout games (it is often called A1Z26). Roman numerals were the everyday way to write numbers in Europe throughout the Middle Ages, until Arabic numerals took over; they had no zero, so a star or slash can mark the gap between words. Czech scout troops sometimes use a 27-letter alphabet where CH is its own letter between H and I.

Try to decode

This message is encrypted with Letter numbers (A1Z26) using the default settings:

16 21 26 26 12 5 19 / 1 18 5 / 6 21 14

Hint

Numbers are separated by spaces, words by a slash. A is 1.

Show solution

PUZZLES ARE FUN

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