AFAIK there is no way to do this built into Inventor.
iPropWiz v5 will be able to do this:
http://www.mcadforums.com/forums/viewtopic.php?f=69&t=11042
--
Sean Dotson, PE
www.mcadforums.com
www.ipropwiz.com
"u32twc" wrote in message news:6401550@discussion.autodesk.com...
> Hi Everyone,
>
> I want to calculate Volume in cubic yards and list it in the parts list on
> my drawing. I've tried an expression in the custom iProperties & BOM. Is
> there a way to calculate it in parameters? I'm using Inventor
> Professional 2010.
>
> Thanks,
> Terri