The calculated distance (air line) between Pyongyang and Chaeryŏng-ŭp is approximately 44 miles respectively 72 kilometers.
By car or train, the actual journey to Chaeryŏng-ŭp is certainly longer, as only the direct route (as the crow flies) between Pyongyang and Chaeryŏng-ŭp has been calculated here.
Air line (approximately)
72 kilometers
39 nautical miles