The calculated distance (air line) between Issoire and Aix-en-Provence is approximately 176 miles respectively 284 kilometers.
By car or train, the actual journey to Aix-en-Provence is certainly longer, as only the direct route (as the crow flies) between Issoire and Aix-en-Provence has been calculated here.
Air line (approximately)
284 kilometers
153 nautical miles