The calculated distance (air line) between San Martín Jilotepeque and Retalhuleu is approximately 62 miles respectively 99 kilometers.
By car or train, the actual journey to Retalhuleu is certainly longer, as only the direct route (as the crow flies) between San Martín Jilotepeque and Retalhuleu has been calculated here.
Air line (approximately)
99 kilometers
53 nautical miles