The calculated distance (air line) between Hachiōji and Nishi-Tokyo-shi is approximately 13 miles respectively 21 kilometers.
By car or train, the actual journey to Nishi-Tokyo-shi is certainly longer, as only the direct route (as the crow flies) between Hachiōji and Nishi-Tokyo-shi has been calculated here.
Air line (approximately)
21 kilometers
11 nautical miles