The calculated distance (air line) between Vert-Saint-Denis and Saint-Quentin-en-Yvelines is approximately 31 miles respectively 50 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 Vert-Saint-Denis and Saint-Quentin-en-Yvelines has been calculated here.
Air line (approximately)
50 kilometers
27 nautical miles