The calculated distance (air line) between Nay Pyi Taw and Sagaing is approximately 148 miles respectively 238 kilometers.
By car or train, the actual journey to Sagaing is certainly longer, as only the direct route (as the crow flies) between Nay Pyi Taw and Sagaing has been calculated here.
Air line (approximately)
238 kilometers
128 nautical miles