Bounding box confusion

[steveBKDRW]

I'm not understanding the design workspace Bounding Box for organic surface or planes. I have an organic surface, did right click on it for properties and then open the Bounding Box. The values are not accurate. I've attached screenshots showing a side view on a grid and with a 1.25" square cube. The grid shows the Z should be approximately 0.5" and not the 1.25". 

If I select the cube, the bounding box properties come out perfect.

Is there another way to get the accurate height of an organic plane or surface?

Steve.

[davebYYPCU]

Delete the cube, remeasure.

Bounding box is including all articles.

Might help….

[steveBKDRW]

I generated the box afterward with the grid to confirm suspicions. Only the surface was used for bounding box. This is my 10th rodeo with this, I've resorted to lying in the CAM but it bothers me.