The calculated distance (air line) between Hwangju-ŭp and Hamhŭng is approximately 128 miles respectively 205 kilometers.
By car or train, the actual journey to Hamhŭng is certainly longer, as only the direct route (as the crow flies) between Hwangju-ŭp and Hamhŭng has been calculated here.
Air line (approximately)
205 kilometers
111 nautical miles