Is there any application from where I can calculate how many frames per second I am getting?
you mean in a video game? for that try FRAPS...
some 3D Accelerator Graphics Cards Driver/Software gives the capability to show some information as a layer upon the game screen while playing.
and if you are about streaming videos then try to play the stream with any player that supports streaming and show such information. I think VLC gives such details while streaming.
I am not so sure about it.