The calculated distance (air line) between Saint-Martin-de-Crau and Clermont-Ferrand is approximately 170 miles respectively 274 kilometers.
By car or train, the actual journey to Clermont-Ferrand is certainly longer, as only the direct route (as the crow flies) between Saint-Martin-de-Crau and Clermont-Ferrand has been calculated here.
Air line (approximately)
274 kilometers
148 nautical miles