Free Excel Column Letter Converter

Convert a column number into its Excel column letter (1 → A, 28 → AB, and so on). Need to go the other way? Try the Excel Column Number Converter.

One number per line, or a comma-separated list. Whole numbers from 1 to 16384 (Excel's max column).

How to convert a column number to a letter

  1. 1

    Enter one or more column numbers

    Type a number, or paste a list - one per line or comma-separated.

  2. 2

    Click "Convert →"

    Each number is turned into its Excel column letter on the right.

Example use cases

1

Writing a formula or macro by column index

Turn a column index from code (like a loop counter) into the letter reference a formula needs.

2

Working with spreadsheet APIs

Many spreadsheet libraries address columns by number - convert to the letter Excel actually shows.

3

Double-checking a wide sheet's layout

Quickly confirm which letter a far-right column (like column 200) corresponds to.

Frequently asked questions

How does the conversion work?

Excel columns use a base-26 letter system with no zero: column 1 is A, column 26 is Z, column 27 is AA, and so on, wrapping the same way a car's odometer would if it only had the letters A-Z.

What is the highest column number Excel supports?

Excel worksheets go up to column 16384, which is letter XFD.

Can I convert several numbers at once?

Yes - enter one number per line, or separate them with commas, and every valid number is converted in one go.

What happens with an invalid or out-of-range number?

That line is skipped in the result and left out, so the output only ever contains valid conversions.