Unlike Microsoft Word, Excel does not have a "Change Case" button. To convert an existing column of text to all caps, you need to use the UPPER function in another column. This function copies the text from your original column and changes its case. After creating a second column with uppercase test, you can copy it and paste its values on top of the original column to convert it.
Click a cell in an empty column in the same row as the first cell you want to convert. For example, if you want to convert text in cells A1 through A10, click inside B1.
Type "=UPPER(" without quotes, then click the first cell to convert and press "Enter." Instead of clicking, you can also type the cell's location after the opening parenthesis.
Double-click the fill handle in the lower-right corner of the cell you just created. This fills the new column with uppercase versions of the text from the original column.
Select all the cells in the uppercase column and copy them by pressing "Control-C."
Right-click the first cell in the original column and click the "123" icon in the Paste Special section to select "Values." This replaces the original column with the uppercase version.
Delete the contents of the second column you created. The original column will retain its new capitalization.
If the column you want to convert doesn't have text in every row, double-clicking the fill handle won't work. Instead, select each cell you want to fill with uppercase and click "Home," "Fill" and then "Down."
Excel has two other functions for changing capitalization: LOWER, which removes caps, and PROPER, which capitalizes the first letter of every word.
In Excel 2013, but not older versions, you can also use Flash Fill. Type the contents of the first cell in your column into the adjacent cell and press "Control-E" to automatically fill the rest. You can then copy the new column and paste it over the original to change its case.
Information in this article applies to Microsoft Excel 2013, 2010 and 2007. It may vary slightly or significantly with other versions.