Highlight Cells That Start with an Alphabet in Excel Using Conditional Formatting

Highlight Cells That Start with an Alphabet in Excel Using Conditional Formatting. 

In Microsoft Excel, you can automatically highlight cells that begin with an alphabet character (A-Z or a-z) using Conditional Formatting with a custom formula. This is useful for data validation, sorting mixed content, or just visually identifying entries that start with letters rather than numbers or special characters.

Formula Used

=ISERR(INT(LEFT(A1,1)))

Formula Description:

LEFT(A1,1)
Extracts the first character of the cell’s content.

INT(LEFT(A1,1))
To convert the first character to a number.

• If the character is a digit (like 1, 2, 3), it will return a number.
• If it’s a letter (like A, B, C), it will throw an error.

ISERR(...)

This checks if the VALUE function throws an error — which happens when the first character is not a number, i.e., when it's an alphabet.

How to Apply This in Excel

Select the range of cells (e.g., A2:A15).

Go to the Home tab → Conditional Formatting → New Rule.

Choose “Use a formula to determine which cells to format.”

Enter the formula:

=ISERR(INT(LEFT(A1,1)))

Click Format, choose your desired fill color (e.g., light green), and press OK.

Pro Tip

If you want to exclude blank cells as well (even if they’re technically "text"), the formula already handles that because ISTEXT("") returns FALSE — so no extra condition is needed!

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