  One of the greatest challenges facing gravitational wave astronomy in the low
frequency band is the confusion noise generated by the vast numbers of
unresolved galactic and extra galactic binary systems. Estimates of the binary
confusion noise suffer from several sources of astrophysical uncertainty, such
as the form of the initial mass function and the star formation rate. There is
also considerable uncertainty about what defines the confusion limit. Various
ad-hoc rules have been proposed, such as the one source per bin rule, and the
one source per three bin rule. Here information theoretic methods are used to
derive a more realistic estimate for the confusion limit. It is found that the
gravitational wave background becomes unresolvable when there is, on average,
more than one source per eight frequency bins. This raises the best estimate
for the frequency at which galactic binaries become a source of noise from 1.45
mHz to 2.54 mHz.
