This is another common issue we encounter in 3D modelling, SolidWorks have provided a special feature to calculate and evaluate the volume parameter.
First, Load the relevant CAD file in Solidworks home screen,
Then select, 'Tools' in the menu bar.
And then chick 'Mass Properties' which displays in the 'Tools' menu.
And then the 'Mass properties' window will pop up. And you'll find the volume and mass of the solid object.