The calculated distance (air line) between Gladbeck and Oer-Erkenschwick is approximately 13 miles respectively 21 kilometers.
By car or train, the actual journey to Oer-Erkenschwick is certainly longer, as only the direct route (as the crow flies) between Gladbeck and Oer-Erkenschwick has been calculated here.
Air line (approximately)
21 kilometers
11 nautical miles