Excel Column Letter & Number Converter
Enter A, AA, XFD or a number from 1 to 16,384; conversion direction is detected automatically.
Enter your values to see a result.
Why Excel columns use letters
Excel uses base-26 alphabetic labels with no zero digit. A is 1, Z is 26, AA is 27 and XFD is 16,384, the last column in modern Excel worksheets.
Worked example
To convert AA, calculate 1×26+1 = 27. Conversely 256 translates to IV. The tool automatically detects whether your entry is letters or a number, regardless of the optional direction selector, and rejects columns outside Excel’s worksheet limit.
Important assumptions and limitations
These are 1-based Excel column references; some programming interfaces use zero-based indexes. Always check which convention your library expects.
How to use this tool
Enter valid input in the fields above and run the calculation or conversion. Review the displayed result, assumptions and any warnings before reusing the output. Where available, download or copy the result directly from your browser.
Frequently asked questions
Is this tool free?
Yes. It works without an account or registration.
Does the tool require a server?
The calculation runs in your browser with local JavaScript. A network connection is only needed to load the website.
Can I use the result professionally?
Check important results against a trusted source, especially for financial, legal and tax decisions. See the stated assumptions for this tool.