The calculated distance (air line) between Santo Tomás La Unión and Chiquimula is approximately 125 miles respectively 201 kilometers.
By car or train, the actual journey to Chiquimula is certainly longer, as only the direct route (as the crow flies) between Santo Tomás La Unión and Chiquimula has been calculated here.
Air line (approximately)
201 kilometers
109 nautical miles