The calculated distance (air line) between Bouc-Bel-Air and Saint-Étienne is approximately 146 miles respectively 235 kilometers.
By car or train, the actual journey to Saint-Étienne is certainly longer, as only the direct route (as the crow flies) between Bouc-Bel-Air and Saint-Étienne has been calculated here.
Air line (approximately)
235 kilometers
127 nautical miles