The calculated distance (air line) between Essen and Katwijk aan den Rijn is approximately 122 miles respectively 196 kilometers.
By car or train, the actual journey to Katwijk aan den Rijn is certainly longer, as only the direct route (as the crow flies) between Essen and Katwijk aan den Rijn has been calculated here.
Air line (approximately)
196 kilometers
106 nautical miles