The calculated distance (air line) between Fontaines-sur-Saône and Saint-Étienne is approximately 35 miles respectively 57 kilometers.
By car or train, the actual journey to Saint-Étienne is certainly longer, as only the direct route (as the crow flies) between Fontaines-sur-Saône and Saint-Étienne has been calculated here.
Air line (approximately)
57 kilometers
31 nautical miles