 The body's very elongated shape had already been indicated by the high brightness variation measured during the photometric observations.According to the survey carried out by the Japanese Akari satellite, "Reinmuthia" measures 24.38 kilometers in diameter and its surface has an albedo of 0.167.The "Collaborative Asteroid Lightcurve Link" assumes a standard albedo for carbonaceous asteroids of 0.057 and derives a diameter of 41.26 kilometers based on an absolute magnitude of 10.65.