The calculated distance (air line) between Nieder-Ingelheim and Gelsenkirchen is approximately 114 miles respectively 183 kilometers.
By car or train, the actual journey to Gelsenkirchen is certainly longer, as only the direct route (as the crow flies) between Nieder-Ingelheim and Gelsenkirchen has been calculated here.
Air line (approximately)
183 kilometers
99 nautical miles