The calculated distance (air line) between Pyongyang and Sŭngho 1-tong is approximately 12 miles respectively 20 kilometers.
By car or train, the actual journey to Sŭngho 1-tong is certainly longer, as only the direct route (as the crow flies) between Pyongyang and Sŭngho 1-tong has been calculated here.
Air line (approximately)
20 kilometers
11 nautical miles