How to Autofill Letters A to Z in Excel (Plus AA, AB, and More)
If you’ve ever needed a quick way to list letters from A to Z in Excel – maybe for labeling, creating IDs, or organizing data – you’ve probably noticed Excel doesn’t offer a built-in feature for it like it does for numbers or weekdays.
But with a few clever formulas and modern Excel functions, you can easily generate alphabets automatically with Excel’s neat autofill feature – and even extend them beyond Z. Here’s how.
Autofill A to Z Using a Simple Formula
Once you know how to autofill A to Z in Excel, you’ll be doing it all the time. Yes, it’s that helpful. Here’s what the process looks like:
1. Type A in a cell.
2. Type =CHAR in the cell below it.
3. In the same cell, continue building the formula by referencing the A. For example, your formula might be =CHAR(A1) if it’s in cell A1.
4. Now type +1, and then close the formula with a final parenthesis so it resembles this: =CHAR(CODE(A1)+1).
5. Press Enter. The letter B should now be present.
6. Select the B and notice the small square at the bottom-right of the cell.
7. Click and hold the square and then drag it down the column. Let go after a few cells. You should see new letters!
Congratulations! You’ve learned how to add the alphabet in Excel without manually typing each letter.
Generate Lowercase Letters
Prefer lowercase? Just tweak the formula slightly:
=CHAR(ROW(A1)+96)
Now you’ll get “a” to “z” as you fill down.
For Excel 365 Users: Use the SEQUENCE Function
If you’re using Excel 365 or Excel 2019+, you can skip the fill handle and instantly generate all letters in one step:
=CHAR(SEQUENCE(26,,65))
This outputs A to Z in a single column. Swap 65 for 97 if you want lowercase.
Generate Letter Pairs Like AA, AB, …, ZZ
Need to continue beyond Z, like in Excel column headers? This formula extends into pairs:
=IF(ROW(A1)<=26, CHAR(ROW(A1)+64), CHAR(INT((ROW(A1)-1)/26)+64)&CHAR(MOD(ROW(A1)-1,26)+65))
This gives you:
– A to Z
– Then AA, AB, …, up to ZZ
Bonus: Create a Custom Alphabet List
If you need to reuse the alphabet often:
Step 1: Manually enter A to Z in a column.
Step 2: Go to File → Options → Advanced → Edit Custom Lists.
Step 3: Import your alphabet into a new list.
Now, typing “A” and dragging down will autofill the rest automatically.
Things to Consider
– SEQUENCE() only works in newer Excel versions (Office 365 and Excel 2019+).
– These formulas use ASCII encoding, which covers standard English characters.
– Triplets like “AAA”, “AAB”, etc., require more advanced logic or VBA.
Summary Table
| Goal | Best Method |
| A–Z (uppercase) | =CHAR(ROW(A1)+64) |
| a–z (lowercase) | =CHAR(ROW(A1)+96) |
| One-shot (Office 365) | =CHAR(SEQUENCE(26,,65)) |
| AA to ZZ | Long formula (see above) |
| Reuse regularly | Create a custom list in Excel |
With these techniques, you’ll save time and effort when working with alphabetical sequences in Excel—whether for tracking, labeling, or organizing.
Tips for Autofilling A to Z in Excel
You don’t necessarily have to start with the letter A; any letter works. Once you reach the end of the alphabet though, this formula will start filling it in with other characters like square brackets, underscore, backtick, and then the letters will start again in small case. It will not start filling in the letters like Excel does for the columns when it runs out of letters.
The formula makes use of the Char function which can fill in ASCII values. These values exist in a series which is what you can use to your advantage but it has its limitations. You can restart the series by typing A in the next cell once you reach Z. Unfortunately, if you try and use AA, AB, and AC, and try and create a series out of it like you can with odd or even numbers, Excel will not follow it.
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Why can’t Excel just do alphabetical fill itself, complete with AA, AB etc when required, instead of having to use hacks like this.
Put some data in the first few cells, then fill down, and Excel figure out the pattern.
It’s a pity AI is used to harvest our data instead of useful functions like this!
If you want to use two letter, you can expand on the one letter handle with the following that copies the first letter than calculate the next one.
=CHAR(CODE(LEFT(A1, 1)) & CHAR(CODE(RIGHT(A1, 1) + 1)
I think your formula might need a relative not an absolute reference — your suggestion got me started but the formula below worked better — I am a novice so I may be wrong — thank you
=char(code(R[-1]C)+1)
I do not know how to write this in A1 format
Brilliant ! Keep up the good work
To make the next consecutive alphabetical list of AA, AB, AC, etc., that imitates Excel columns, assume”A” is visible in cell A2. Restart by typing “AA” in the cell after “Z”. Then in the next cell insert the formula =CONCATENATE(($A$2),CHAR(CODE($A2)+1)). Draw the formula down to make a column or row of labels that mimic the Excel double-letter pattern through AZ. Restart again by typing BA, then write another similar formula that concatenates a static “B” cell ($), with the added A-Z characters. Do it again & again until ZZ if you wish. It isn’t wholly auto-fill, but it gets there.