Convert the cell to text values if it contains a number or formula and you want to make only part of the cell subscript. If you want the entire cell to be subscript, leave it as is. To convert a cell to text, right-click the cell, choose "Format Cells," select the "Number" tab, select "Text," and then click "OK."
Enter the characters you want to display in subscript using the default font size, if they are not already in the cell.
Select the cell or the text you want to convert.
Right-click the selection and choose "Format Cells" to open the Cell Formatting dialog box.
Click the box next to "Subscript" under the Font tab, and then click "OK." The selected cells or text displays as subscript characters.