The calculated distance (air line) between Joinville-le-Pont and Cergy-Pontoise is approximately 23 miles respectively 37 kilometers.
By car or train, the actual journey to Cergy-Pontoise is certainly longer, as only the direct route (as the crow flies) between Joinville-le-Pont and Cergy-Pontoise has been calculated here.
Air line (approximately)
37 kilometers
20 nautical miles