The calculated distance (air line) between Höhr-Grenzhausen and Gelsenkirchen is approximately 78 miles respectively 126 kilometers.
By car or train, the actual journey to Gelsenkirchen is certainly longer, as only the direct route (as the crow flies) between Höhr-Grenzhausen and Gelsenkirchen has been calculated here.
Air line (approximately)
126 kilometers
68 nautical miles