To do Alt + H 3 D on Mac in Excel, download and install Accelerator Keys, then press Option, followed by H, 3, D.
Command: Double Underline
This is how to do Alt + H 3 D 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 3 D applies a double underline to the selected cells. This is commonly used in accounting to indicate final totals or grand totals.