The calculated distance (air line) between San Gavino Monreale and Sant'Antioco is approximately 38 miles respectively 61 kilometers.
By car or train, the actual journey to Sant'Antioco is certainly longer, as only the direct route (as the crow flies) between San Gavino Monreale and Sant'Antioco has been calculated here.
Air line (approximately)
61 kilometers
33 nautical miles