Beam Length Tag?

[mark.62793]

I would like to add the length of all my beams to my existing beam tag. However, when i try to add it when editing the label for the tag, there is no Length option available? However on all my beams, under the dimensions section the length is shown?

Am i stuck making a shared parameter in each of my beam types, then linking that to my beam tag?

My goal is to have my tag look like ........4x10 x 15'-4"+/-

Thanks for any help!

Mark