Free Excel Column Number Converter
Convert an Excel column letter into its column number (A → 1, AB → 28, and so on). Need to go the other way? Try the Excel Column Letter Converter.
One letter per line, or a comma-separated list. Letters A-Z only, up to XFD (Excel's max column).
How to convert a column letter to a number
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1
Enter one or more column letters
Type a letter, or paste a list - one per line or comma-separated.
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2
Click "Convert →"
Each letter is turned into its Excel column number on the right.
Example use cases
Translating a cell reference into code
Turn a column letter from a formula or reference into the numeric index a script or API expects.
Working with spreadsheet APIs
Many spreadsheet libraries address columns by number - convert from the letter Excel shows.
Checking how far right a column is
Quickly find out how many columns in a letter like "BZ" actually is.
Frequently asked questions
How does the conversion work?
Excel columns use a base-26 letter system with no zero: A is column 1, Z is column 26, AA is column 27, and so on - each extra letter is worth 26 times the place before it.
What is the highest column letter Excel supports?
Excel worksheets go up to letter XFD, which is column 16384.
Is the input case-sensitive?
No - lowercase letters are treated the same as uppercase.
What happens with an invalid entry?
A line that isn't made up of letters A-Z, or that resolves past column 16384, is skipped and left out of the result.