  The invariant four-volume $\mathcal{V}$ of a complete black hole (the volume
of the spacetime at and interior to the horizon) diverges. However, if one
considers the black hole set up by the gravitational collapse of an object, and
integrates only a finite time to the future of the collapse, the resultant
volume is well defined and finite. In this paper we examine non-degenerate
stationary black holes (and cosmological horizons) and find that
$\mathcal{V}_{s} \varpropto \ln(\lambda)$ where $s$ is any shell that
terminates on the horizon, $\lambda$ is the affine generator of the horizon and
the constant of proportionality is the Parikh volume of $s$ divided by the
surface gravity. This provides an alternative local and invariant definition of
the surface gravity of a stationary black hole.
