The calculated distance (air line) between Saint-Sébastien-sur-Loire and Orléans is approximately 166 miles respectively 267 kilometers.
By car or train, the actual journey to Orléans is certainly longer, as only the direct route (as the crow flies) between Saint-Sébastien-sur-Loire and Orléans has been calculated here.
Air line (approximately)
267 kilometers
144 nautical miles