The calculated distance (air line) between Caudry and Saint-Quentin-en-Yvelines is approximately 113 miles respectively 181 kilometers.
By car or train, the actual journey to Saint-Quentin-en-Yvelines is certainly longer, as only the direct route (as the crow flies) between Caudry and Saint-Quentin-en-Yvelines has been calculated here.
Air line (approximately)
181 kilometers
98 nautical miles