The calculated distance (air line) between Alor Setar and Bukit Mertajam is approximately 53 miles respectively 85 kilometers.
By car or train, the actual journey to Bukit Mertajam is certainly longer, as only the direct route (as the crow flies) between Alor Setar and Bukit Mertajam has been calculated here.
Air line (approximately)
85 kilometers
46 nautical miles