The calculated distance (air line) between Souppes-sur-Loing and Saint-Quentin-en-Yvelines is approximately 52 miles respectively 84 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 Souppes-sur-Loing and Saint-Quentin-en-Yvelines has been calculated here.
Air line (approximately)
84 kilometers
45 nautical miles