  We use the GALPROP code for cosmic-ray (CR) propagation to calculate the
broad-band luminosity spectrum of the Milky Way related to CR propagation and
interactions in the interstellar medium. This includes gamma-ray emission from
the production and subsequent decay of neutral pions, bremsstrahlung, and
inverse Compton scattering, and synchrotron radiation. The Galaxy is found to
be nearly a CR electron calorimeter, but {\it only} if gamma ray emitting
processes are taken into account. Synchrotron radiation alone accounts for only
one third of the total electron energy losses with ~10-20% of the total
synchrotron emission from secondary CR electrons and positrons. The
relationship between far-infrared and radio luminosity that we find from our
models is consistent with that found for galaxies in general. The results will
be useful for understanding the connection between diffuse emissions from radio
through gamma rays in ``normal'' (non-AGN dominated) galaxies, as well as for
estimating the broad-band extragalactic diffuse background from these kinds of
galaxies.
