The calculated distance (air line) between Bochum-Hordel and Ridderkerk is approximately 113 miles respectively 182 kilometers.
By car or train, the actual journey to Ridderkerk is certainly longer, as only the direct route (as the crow flies) between Bochum-Hordel and Ridderkerk has been calculated here.
Air line (approximately)
182 kilometers
98 nautical miles