How to Convert Letters to Numbers with A1Z26

A1Z26 is the most intuitive cipher you will ever learn: A equals 1, B equals 2, all the way through Z equals 26. The whole system fits on a single index card, which is exactly why it has been used in classrooms, escape rooms, puzzle hunts, and casual games for decades. Our Letters to Numbers Converter handles the conversion instantly so you can focus on the puzzle, not the arithmetic.

The Full A1Z26 Mapping

Every letter has one number. There are no exceptions and no special characters to memorize.

Letter	Number	Letter	Number	Letter	Number
A	1	J	10	S	19
B	2	K	11	T	20
C	3	L	12	U	21
D	4	M	13	V	22
E	5	N	14	W	23
F	6	O	15	X	24
G	7	P	16	Y	25
H	8	Q	17	Z	26
I	9	R	18

Encoding Common Words: Real Examples

Seeing A1Z26 in action is the fastest way to understand how it works. Here are a few common words with their full encodings:

• HELLO → 8-5-12-12-15
• WORLD → 23-15-18-12-4
• CODE → 3-15-4-5
• APPLE → 1-16-16-12-5
• SECRET → 19-5-3-18-5-20

Notice that the numbers are separated by hyphens within a word. This is the standard convention because without separators, a sequence like 1-12-12 could be misread as 11-2 or 112. Hyphens between letter-numbers, and spaces or slashes between words, make decoding unambiguous.

Encoding a Full Sentence

For a complete sentence, you encode each word separately and leave a gap between words. The sentence "MEET AT NOON" becomes:

13-5-5-20 / 1-20 / 14-15-15-14

Slashes separate words, hyphens separate the numbers within each word. Anyone with the A1Z26 key can decode it correctly because the structure is unambiguous. If you are designing a puzzle, you can also drop the slashes and challenge the solver to figure out word boundaries — that is a significantly harder variant.

Where A1Z26 Is Genuinely Useful

Escape Rooms and Puzzle Hunts

A1Z26 is one of the most common ciphers in escape room design because it requires no special equipment and no prior knowledge. A clue can say "decode: 8-5-12-16" and any adult can work it out with the right key. The Letters to Numbers Converter and Numbers to Letters Converter let puzzle designers rapidly verify their clue sets and test the solve path.

Classroom Cipher Exercises

Teachers use A1Z26 to introduce the concept of encoding and decoding. Students can encode their name, trade messages with classmates, and decode each other's output. It is hands-on, requires no technology, and teaches the fundamental idea that information can be represented in multiple forms.

Lightweight Message Encoding

A1Z26 is not cryptographically secure — anyone who knows the system can decode it instantly. But it is useful for situations where you want mild obfuscation: a fun way to pass a note, a game mechanic, or a novelty. For anything that needs real security, use a proper encryption tool instead.

Word Boundary Handling: The Important Detail

The single biggest source of A1Z26 decoding errors is inconsistent word boundary markers. If you encode a message without clear separators, the decoder has to guess where one word ends and another begins. Standard practice:

• Use hyphens between number groups within a word.
• Use spaces or slashes between words.
• Keep punctuation out of the encoded sequence, or define a convention for it.

Our Letters to Numbers Converter applies consistent formatting automatically, so you do not have to think about separators manually. To go back the other direction, use Numbers to Letters Converter.

Variations on the A1Z26 System

Some puzzle designers modify the basic A1Z26 system to add a layer of difficulty. Common variations include reversing the alphabet (Z=1, A=26), using a shifted alphabet (B=1, C=2), or combining A1Z26 with a Caesar cipher shift. When you encounter a number sequence that does not decode cleanly with standard A1Z26, trying a reversed or shifted alphabet is the natural next step. The basic principle — letters map to positions — stays the same across all of these variants.