The calculated distance (air line) between Pyin Oo Lwin and Loikaw is approximately 170 miles respectively 274 kilometers.
By car or train, the actual journey to Loikaw is certainly longer, as only the direct route (as the crow flies) between Pyin Oo Lwin and Loikaw has been calculated here.
Air line (approximately)
274 kilometers
148 nautical miles