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