To do Alt + H F G on Mac in Excel, download and install Accelerator Keys, then press Option, followed by H, F, G.
Command: Increase Font Size
This is how to do Alt + H F G on Mac in Excel with Accelerator Keys, the native ribbon and alt key shortcut solution for Mac users who get more done with Excel.
Alt + H F G increase Font Size makes the text in selected cells larger. Each click increases the size to the next standard font size.