If the binary consists of a pair of neutron stars, their merger will be accompanied by a kilonova / hypernova explosion that may allow the position to be accurately identified by electromagnetic telescopes. In such cases, the redshift of the host galaxy allows a determination of the Hubble constant H 0 . This was the case for GW170817, which was used to make the first such measurement. Even if no electromagnetic counterpart can be identified for an ensemble of signals, it is possible to use a statistical method to infer the value of H 0 .