The calculated distance (air line) between Phnom Penh and Kampong Chhnang is approximately 50 miles respectively 81 kilometers.
By car or train, the actual journey to Kampong Chhnang is certainly longer, as only the direct route (as the crow flies) between Phnom Penh and Kampong Chhnang has been calculated here.
Air line (approximately)
81 kilometers
44 nautical miles