The calculated distance (air line) between Siem Reap and Kampong Chhnang is approximately 94 miles respectively 151 kilometers.
By car or train, the actual journey to Kampong Chhnang is certainly longer, as only the direct route (as the crow flies) between Siem Reap and Kampong Chhnang has been calculated here.
Air line (approximately)
151 kilometers
82 nautical miles