The calculated distance (air line) between Phnom Penh and Cần Thơ is approximately 121 miles respectively 195 kilometers.
By car or train, the actual journey to Cần Thơ is certainly longer, as only the direct route (as the crow flies) between Phnom Penh and Cần Thơ has been calculated here.
Air line (approximately)
195 kilometers
105 nautical miles