The calculated distance (air line) between Ouderkerk aan de Amstel and Apeldoorn is approximately 45 miles respectively 73 kilometers.
By car or train, the actual journey to Apeldoorn is certainly longer, as only the direct route (as the crow flies) between Ouderkerk aan de Amstel and Apeldoorn has been calculated here.
Air line (approximately)
73 kilometers
39 nautical miles