  In this note, we extend the Bridgeman-Kahn identity to all finite-volume
orientable hyperbolic $n$-manifolds with totally geodesic boundary. In the
compact case, Bridgeman and Kahn are able to express the manifold's volume as
the sum of a function over only the orthospectrum. For manifolds with
non-compact boundary, our extension adds terms corresponding to intrinsic
invariants of boundary cusps.
