The calculated distance (air line) between Le Chesnay and Marne La Vallée is approximately 24 miles respectively 38 kilometers.
By car or train, the actual journey to Marne La Vallée is certainly longer, as only the direct route (as the crow flies) between Le Chesnay and Marne La Vallée has been calculated here.
Air line (approximately)
38 kilometers
21 nautical miles