  In this paper we use an RXTE library of spectral models from 10 black-hole
and 9 pulsar X-ray binaries, as well as model spectra available in the
literature from 13 extra-galactic Ultra-luminous X-ray sources (ULXs). We
compute average bolometric corrections (BC=$\mathrm{L_{band}/L_{bol}}$) for our
sample as a function of different accretion rates. We notice the same behaviour
between black-hole and pulsars BCs only when ULX pulsars are included. These
measurements provide a picture of the energetics of the accretion flow for an
X-ray binary based solely on its observed luminosity in a given band. Moreover
it can be a powerful tool in X-ray binary population synthesis models.
Furthermore we calculate the X-ray (2-10 keV) to optical (V-band) flux ratios
at different Eddington ratios for the black-hole X-ray binaries in our sample.
This provides a metric of the maximum contribution of the disk to the optical
emission of a binary system and better constraints on its nature (donor type
etc). We find that the optical to X-ray flux ratio shows very little variation
as a function of accretion rate, but testing for different disk geometries
scenarios we find that the optical contribution of the disk increases as the
$p$ value decreases ($T(r)\sim r^{-p}$). Moreover observational data are in
agreement with a thicker disk scenario ($p<0.65$), which could also possibly
explain the lack of observed high-inclination systems.
