The calculated distance (air line) between Le Mesnil-le-Roi and Cormeilles-en-Parisis is approximately 4 miles respectively 7 kilometers.
By car or train, the actual journey to Cormeilles-en-Parisis is certainly longer, as only the direct route (as the crow flies) between Le Mesnil-le-Roi and Cormeilles-en-Parisis has been calculated here.
Air line (approximately)
7 kilometers
4 nautical miles