Hello I am a student from Belgium and I have a project with an assembly the assembly is pretty big and has around 30-40 parts on it.

I am trying to calculate the total area of the assembly so I know how much paint etc it would take to paint it.

I have tried using the measuring tool but as far as I know I have to select every individual piece on my assembly witch is quite simply going to take me forever to do.

Is there any other way to do this?

Thanks in advance
Jonas