The calculated distance (air line) between Elche and Sant Joan d'Alacant is approximately 17 miles respectively 28 kilometers.
By car or train, the actual journey to Sant Joan d'Alacant is certainly longer, as only the direct route (as the crow flies) between Elche and Sant Joan d'Alacant has been calculated here.
Air line (approximately)
28 kilometers
15 nautical miles