Letter to Number Converter (A1Z26)

How to use the letters to numbers (a1z26)

1. Type or paste your text into the Input box. You can enter letters like HELLO or numbers like 8-5-12-12-15.
2. Choose a Direction: auto-detect, letters to numbers, or numbers to letters.
3. Pick a Number separator (hyphen, space or comma) for how encoded output should look.
4. Toggle Keep word spaces if you want spaces between words preserved during encoding.
5. The result appears instantly below as you type.

How the A1Z26 cipher works

The A1Z26 cipher is one of the simplest substitution methods. Each letter of the English alphabet is replaced by its position number: A becomes 1, B becomes 2, and so on up to Z which becomes 26. To encode the word "CAT", you look up each letter: C is 3, A is 1, T is 20, giving 3-1-20 when using a hyphen separator.

Decoding reverses the process. Given 4-15-7, you map 4 to D, 15 to O and 7 to G, spelling "DOG". Non-alphabetic characters such as punctuation are typically ignored or stripped, while spaces between words can be kept as double separators or removed entirely depending on your preference.

Alphabet to number reference table

Use this table to look up any letter's numeric value without running the converter.

Practical uses for alphabet numbers

Converting letters to numbers is common in puzzle solving, cryptography games and escape rooms. Many geocaching puzzles use A1Z26 as a first step before applying more complex ciphers. Teachers also use it to introduce students to the idea of encoding information.

In programming challenges, mapping characters to their alphabetical index helps with tasks like calculating string scores or building simple hash functions. If you need phonetic clarity rather than numeric conversion, the NATO phonetic alphabet spells out words using standardized code words instead.

Common mistakes to avoid

A frequent error is mixing up zero-indexed and one-indexed positions. In computing, arrays often start at 0, but the A1Z26 cipher always starts at 1 for A. Using 0 for A will shift every letter and produce incorrect decodings.

Another issue is inconsistent separators. If you encode with hyphens but try to decode a comma-separated string without switching the mode, the parser may read the entire sequence as one invalid number. Always match the separator used during encoding when decoding manually.

Finally, non-English characters like accented letters do not have standard A1Z26 values. Strip diacritics first or handle them separately before passing text through a letter to number converter.

A1Z26 compared to other encodings

A1Z26 is not encryption. Anyone who sees a sequence of numbers between 1 and 26 can guess the scheme immediately. For actual secrecy, combine it with a key-based cipher or use something stronger. If you need to represent text in a compact machine-readable format, consider Base64 encoding instead, which handles all byte values and preserves binary data safely.

For translating dots and dashes rather than numbers, a Morse code translator serves a similar educational purpose but uses an entirely different symbol set. And if you are working with numeral systems rather than alphabets, a number base converter handles binary, octal and hexadecimal transformations.

Worked examples

Each result below was produced by the same code the tool runs, so you can check your own numbers against them.