The calculated distance (air line) between Kelkheim-Mitte and Düsseldorf is approximately 105 miles respectively 169 kilometers.
By car or train, the actual journey to Düsseldorf is certainly longer, as only the direct route (as the crow flies) between Kelkheim-Mitte and Düsseldorf has been calculated here.
Air line (approximately)
169 kilometers
91 nautical miles