Thank you for the effort. I tested and encountered a problem with the method by Chris (coded by Jim):

@jim said:

What Chris said:

> bb = Geom;;BoundingBox.new
> Sketchup.active_model.selection.each { |e| bb.add(e.bounds) }
> 

bounds is not a method of Entity and hence the code failed to execute. Should I step into each entity to retrieve DrawingElement objects in order to get the BoundingBox?

On the other hand, I tested TIG's codes and replaced center=ssg.bounds.center by the followings to check the size of the box:

puts "Width; #{ssg.bounds.width}\nHeight; #{ssg.bounds.height}\nDepth; #{ssg.bounds.depth}"

These are the results (Tested with my SU Pro 7.0.10247):

Without Sang:

===== Without Sang ====
Width; ~ 12' 7/8"
Height; ~ 9' 5 1/2"
Depth; 6' 11 3/4"

With Sang:

==== With Sang =====
Width; ~ 12' 7/8"
Height; ~ 9' 5 1/2"
Depth; ~ 11' 6 1/2"

I just wonder why:
(1) bounds.depth returns the height and bounds.height returns the depth...?
(2) Sang affects the bounding box in depth that much...

Dear all,

Would you advise whether it is possible to retrieve the size(x,y,z) of the bounding box of selected entities, without looping and comparing the sizes of each entities?

Sorry for my bad English, perhaps the following picture helps illustrating my question.
Thank you very much