The calculated distance (air line) between Pyin Oo Lwin and Mawlaik is approximately 172 miles respectively 276 kilometers.
By car or train, the actual journey to Mawlaik is certainly longer, as only the direct route (as the crow flies) between Pyin Oo Lwin and Mawlaik has been calculated here.
Air line (approximately)
276 kilometers
149 nautical miles