Excel Column Converter
Find out which number a column letter stands for, or which letters belong to a column number. Type AA to get 27, 16384 to get XFD, or a cell reference to switch between A1 and R1C1 notation. A whole list can be converted at once.
- Runs in your browser
- No sign-up
- Free to use
Letters are converted to numbers and numbers to letters. A1-style references such as BC12 and R1C1-style references such as R12C55 are converted into each other.
How to use Excel Column Converter
- Type or paste values, one per line: letters, numbers or cell references.
- Read the result next to each line; conversion happens as you type.
- Check the note column for references that fall outside the Excel grid.
- Select Copy results to copy the converted values as a list.
Excel Column Converter features
Letters to numbers
A is 1, Z is 26, AA is 27 and so on up to XFD, the last Excel column.
Numbers to letters
Any column index is turned back into its letter name.
A1 and R1C1 references
BC12 becomes R12C55 and the reverse, including references with dollar signs.
Bulk conversion
Up to 500 lines at a time, with the kind of each input shown.
Grid limits
Warns when a column or row lies beyond XFD or row 1,048,576.
Instant and offline
A small calculation in your browser, no upload involved.
When to use Excel Column Converter
- Writing a VLOOKUP and needing the index of a column far to the right.
- Translating between spreadsheet references and zero- or one-based column indexes in code.
- Reading a macro or a formula recorded in R1C1 style.
- Checking which column a data import will place a field in.
Excel Column Converter FAQ
How are column letters turned into numbers?
The letters form a number in base 26 without a zero: A to Z are 1 to 26, AA is 26 + 1 = 27, AZ is 52, BA is 53. For three letters, the first is multiplied by 676, the second by 26, and the third is added. XFD is 24 × 676 + 6 × 26 + 4 = 16,384.
What is the last column in Excel?
XFD, column 16,384, in every version since Excel 2007. Older .xls workbooks end at IV, column 256. Google Sheets has no fixed last column but limits a spreadsheet to ten million cells.
What is R1C1 notation?
An alternative way to write cell references in which both the row and the column are numbers: R12C55 is row 12, column 55, the same cell as BC12. Excel can display formulas this way, and it is common in recorded macros because relative references are easy to express.
Why do programming libraries give a different number?
Many libraries count from zero, so column A is 0 and AA is 26. The results here are one-based, like Excel's COLUMN function. Subtract one for zero-based code.
Are dollar signs handled?
Yes. Absolute references such as $B$2 are read the same as B2; the dollar signs only affect copying in a spreadsheet and do not change which cell is meant.
How do I get a column number inside Excel itself?
Use =COLUMN(AA1) for the number of a column, and =SUBSTITUTE(ADDRESS(1,27,4),"1","") for the letters of column 27.
Why spreadsheet columns have letters
The letters across the top of a spreadsheet go back to the first electronic spreadsheets of the late 1970s, which labelled columns with letters and rows with numbers so that a cell could be named compactly, as in B7. The scheme is easy to read while a sheet is small. It becomes awkward further right: few people can say offhand that column CV is the hundredth.
Functions and code, however, mostly want numbers. VLOOKUP asks for the index of the column to return, INDEX takes a column number, and every programming library that reads spreadsheets addresses columns numerically. Converting between the two is simple arithmetic, yet it is unusual arithmetic. The letters behave like a base-26 number system that has no digit for zero, which is why the step from Z to AA trips people up and why hand calculation is error-prone.
The R1C1 reference style avoids letters altogether. It writes both coordinates as numbers and expresses relative positions with brackets, for example R[-1]C for the cell one row above. Formulas written this way are identical in every row of a filled column, which makes them easier to audit, and Excel's macro recorder uses the style for that reason. Anyone who maintains VBA code eventually needs to translate between the two notations.
The converter also checks references against the limits of the grid. A reference such as ZZZ1 is syntactically fine and lies far outside what a sheet can hold, a useful thing to know before building a formula around it.