The calculated distance (air line) between Smach Mean Chey and Kampong Cham is approximately 167 miles respectively 269 kilometers.
By car or train, the actual journey to Kampong Cham is certainly longer, as only the direct route (as the crow flies) between Smach Mean Chey and Kampong Cham has been calculated here.
Air line (approximately)
269 kilometers
145 nautical miles