Excel Column Number to Letter

How it works

Excel numbers its columns sequentially: column 1 is A, column 26 is Z, column 27 is AA, column 28 is AB, and so on. This tool performs the reverse conversion — from number to letter — using the same base-26 system.

This is particularly useful when working with functions like ADDRESS or INDIRECT, or when writing VBA code that iterates over columns using numeric indexes and needs to reference them by letter.

The tool supports all valid Excel columns from 1 (A) to 16384 (XFD).

The formula, for Excel and Google Sheets

With the number in A1, both spreadsheets use the same formula:

=SUBSTITUTE(ADDRESS(1,A1,4),"1","")

The 4 asks for a relative reference, which is what leaves the letter alone without a $. To go the other way, see the column letter to number tool.

Where it stops, and why

• 1 to 16384 is the whole range. Column 16384 is XFD, the last column a worksheet has. Anything larger is rejected rather than given a letter Excel would not accept.
• Past 702 you need three letters. 702 is ZZ and 703 is AAA. A formula that only handles two letters silently produces nonsense from there on.
• There is no zero. 1 is A, so there is no column 0 and no empty letter. The numbering is bijective base 26, which is why dividing by 26 the ordinary way lands one short at every multiple.
• Decimals and negatives are refused. A column number is a whole number from 1 up; anything else is flagged rather than rounded into a wrong answer.
• Batch reports what it rejected. Values it cannot convert stay in the table with the reason, so the output lines up with what you pasted.