The calculated distance (air line) between Grand-Couronne and Cergy-Pontoise is approximately 53 miles respectively 85 kilometers.
By car or train, the actual journey to Cergy-Pontoise is certainly longer, as only the direct route (as the crow flies) between Grand-Couronne and Cergy-Pontoise has been calculated here.
Air line (approximately)
85 kilometers
46 nautical miles