The calculated distance (air line) between Pyŏksŏng-ŭp and Tŏkch’ŏn is approximately 124 miles respectively 199 kilometers.
By car or train, the actual journey to Tŏkch’ŏn is certainly longer, as only the direct route (as the crow flies) between Pyŏksŏng-ŭp and Tŏkch’ŏn has been calculated here.
Air line (approximately)
199 kilometers
107 nautical miles