Box Selection: Repeating selection Blender 2.8.

Edit Mode

I press the B key and drag out a particular selection. I want to repeat that exact size box selection on another portion of the mesh. How would I go about this? I have a fairly dense mesh and I want to avoid actually counting the box selected faces in order to repeat the same size selection on another part of my model.
Select &gt; Mirror Selection
but this only works if your model is symmetrical
otherwise I don't know an easy way to repeat same size selection