The calculated distance (air line) between Nay Pyi Taw and Yamethin is approximately 47 miles respectively 76 kilometers.
By car or train, the actual journey to Yamethin is certainly longer, as only the direct route (as the crow flies) between Nay Pyi Taw and Yamethin has been calculated here.
Air line (approximately)
76 kilometers
41 nautical miles