The calculated distance (air line) between Châteaugiron and Cergy-Pontoise is approximately 178 miles respectively 286 kilometers.
By car or train, the actual journey to Cergy-Pontoise is certainly longer, as only the direct route (as the crow flies) between Châteaugiron and Cergy-Pontoise has been calculated here.
Air line (approximately)
286 kilometers
154 nautical miles