Calculate estimated model size in screen space?

Hi all,
Is there a simple way to calculate estimated 3d model size in screen space, ie given camera and a model (or bounding sphere) how many pixels it will use on screen?

I tried multiplying bounding sphere with view-projection matrix but I’m getting strange results.


Nevermind, forgot about GraphicsDevice.Viewport.Project, I can just use it to get corners and check distance.