The calculated distance (air line) between Saint-Quentin-en-Yvelines and Caen is approximately 112 miles respectively 180 kilometers.
By car or train, the actual journey to Caen is certainly longer, as only the direct route (as the crow flies) between Saint-Quentin-en-Yvelines and Caen has been calculated here.
Air line (approximately)
180 kilometers
97 nautical miles