The calculated distance (air line) between Kampong Chhnang and Sihanoukville is approximately 137 miles respectively 221 kilometers.
By car or train, the actual journey to Sihanoukville is certainly longer, as only the direct route (as the crow flies) between Kampong Chhnang and Sihanoukville has been calculated here.
Air line (approximately)
221 kilometers
119 nautical miles