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