The calculated distance (air line) between Phnom Penh and Cao Lãnh is approximately 90 miles respectively 145 kilometers.
By car or train, the actual journey to Cao Lãnh is certainly longer, as only the direct route (as the crow flies) between Phnom Penh and Cao Lãnh has been calculated here.
Air line (approximately)
145 kilometers
78 nautical miles