Hi Tony, sorry no there is not any method currently in MoI to obtain the volume of a solid, you will need to export your model to a different CAD program in order to do that. ViaCAD is an inexpensive helper program to use for that: http://www.punchcad.com/p-9-viacad-2d3d-v8.aspx .

You can also export to STL format and there are various STL display/inspection programs that you can use which usually have volume calculations with them, here's one:
http://software.materialise.com/minimagics

I do plan on adding a volume calculation method in the future.

- Michael