The calculated distance (air line) between Batu Arang and Bukit Mertajam is approximately 157 miles respectively 253 kilometers.
By car or train, the actual journey to Bukit Mertajam is certainly longer, as only the direct route (as the crow flies) between Batu Arang and Bukit Mertajam has been calculated here.
Air line (approximately)
253 kilometers
137 nautical miles