The calculated distance (air line) between Cergy-Pontoise and Champigny-sur-Marne is approximately 24 miles respectively 39 kilometers.
By car or train, the actual journey to Champigny-sur-Marne is certainly longer, as only the direct route (as the crow flies) between Cergy-Pontoise and Champigny-sur-Marne has been calculated here.
Air line (approximately)
39 kilometers
21 nautical miles