How to recognize the magnification factor in 3D Viewer

I want to place two 3D models side by side. I want them to have the same magnification factor in the 3D Viewer so that I can compare them visually.
Where do I get the magnification factor?

Thank you for your help

You can click the link view button to make the two views use exactly the same camera settings.

Note that if you use perspective projection (this is the default) then there is no constant zoom factor (size depends on distance from camera). Therefore, if you want to show the scene from different directions then you need to switch to parallel (a.k.a. orthogonal) projection mode.