The calculated distance (air line) between Cergy-Pontoise and Rueil-Malmaison is approximately 12 miles respectively 20 kilometers.
By car or train, the actual journey to Rueil-Malmaison is certainly longer, as only the direct route (as the crow flies) between Cergy-Pontoise and Rueil-Malmaison has been calculated here.
Air line (approximately)
20 kilometers
11 nautical miles