The Secondary Dimensions function allows you to add metric unit equivalents to dimension values displayed in feet and inches, and vice versa. The Secondary Dimensions menu is located at Document > Annotation.
Note: If your program does not display the Secondary Dimensions menu, you can add it to your work environment.
Use the Document > Annotation > Secondary Dimensions > Convert Dimensions dialog box to set the unit and the number of decimals of the converted dimension value.
Click OK, and the secondary values will appear on the opposite side of the dimension line.
Choose Document > Annotation > Secondary Dimensions > Refresh converted dimensions to update both the value and the location of the dimension. Again, this command will work on either all dimensions (if nothing is selected) or selected ones.
If you do not need equivalents any more, simply choose Remove converted dimensions from the Secondary Dimensions menu.