Excel Column Number to Letter

What this does

Excel addresses columns two ways: letters (A, B, …, Z, AA, …, XFD) in the interface, and numbers (1 to 16384) in functions like COLUMN, ADDRESS, OFFSET, and in VBA. The letters are bijective base-26 — after Z comes AA, after AZ comes BA — which is why "what number is column AB" is not obvious mental math (it is 28). Keep the inputs visible and clearly labelled and the whole thing stays auditable — anyone who opens the file later, including you, can see at a glance exactly what feeds the result and change one assumption without hunting through the formula. The difference between a quick fix and a sheet you can trust is the extra minute you spend validating “excel column number to letter”. Start on a copy or a tiny sample, keep the affected columns visible, and compare the result with the tool above before you touch the real workbook. When a formula is involved, keep the inputs labelled beside it, reference cells instead of typing values, and apply number formatting only after the result checks out. The point is a layout choice that keeps the sheet readable and sortable, but the practical win is that someone else can open the file and understand what happened without asking you.

A worked example

You need the letter for column 28 to build a range in a macro. =SUBSTITUTE(ADDRESS(1,28,4),"1","") returns AB: ADDRESS(1,28,4) builds the relative reference AB1, and SUBSTITUTE strips the row number. In the other direction, =COLUMN(INDIRECT("AB1")) returns 28. Macro authors, formula builders, and anyone wiring OFFSET/INDEX ranges constantly translate between the letter the sheet shows and the number the function needs. A practical tip before you scale it up: build it once on a small block of test data, confirm the number against the tool on this page, and only then point it at your real sheet. That one habit catches almost every mistake while it is still cheap to fix, long before a wrong figure reaches a report or a colleague.

In Google Sheets

Everything above works in Google Sheets too. Excel and Sheets share the formula syntax used here; only the surrounding menus are arranged differently. That portability is deliberate — learn it once and it follows you between the two tools and across Windows and Mac. Keep this page bookmarked for the next time the same question comes up. Better still, rebuild the example once in your own sheet — doing it yourself, with the tool above to check against, is what turns a copied formula into a technique you own. The short version of “excel column number to letter”: the answer is at the top of this page, the tool proves it on your own numbers, and the sections above explain why it holds so the next variation does not stump you. Excel rewards people who reference cells instead of typing values and who keep inputs separate from formulas, because that is what makes a result you can audit months later. Build it once, deliberately, with the live tool as a check, and you convert a one-off lookup into a reusable skill — which is the whole point of learning the why and not just the what.

Common mistakes

• Assuming AA is 27 because "A is 1, so AA is 26+1" — correct, but AZ→BA trips people up; it is base-26 with no zero digit.
• Using ADDRESS without the 4 (abs_num) argument and getting $AB$1 with dollar signs.
• INDIRECT-based letter→number formulas breaking when the cell contains a trailing space.
• Hard-coding column letters in VBA that shift when columns are inserted — use named ranges or Cells(row, col).

Frequently asked questions