The calculated distance (air line) between Dudenhofen and Mönchengladbach is approximately 155 miles respectively 249 kilometers.
By car or train, the actual journey to Mönchengladbach is certainly longer, as only the direct route (as the crow flies) between Dudenhofen and Mönchengladbach has been calculated here.
Air line (approximately)
249 kilometers
135 nautical miles