Provided is a method and apparatus for calculating an isolation distance that is a distance where an interference phenomenon does not occur between wireless repeater apparatuses. The isolation distance calculating apparatus may include: an interference signal calculator to calculate a magnitude of an interference signal included in a particular band by detecting a signal of the particular band extracted from a received radio signal of a wireless repeater apparatus; and an isolation distance calculator to calculate a necessary isolation distance for cancelling interference between the wireless repeater apparatus and another wireless repeater apparatus, based on a predetermined allowable interference signal level and the magnitude of the interference signal.