The calculated distance (air line) between Mường Lay and Thái Nguyên is approximately 176 miles respectively 284 kilometers.
By car or train, the actual journey to Thái Nguyên is certainly longer, as only the direct route (as the crow flies) between Mường Lay and Thái Nguyên has been calculated here.
Air line (approximately)
284 kilometers
153 nautical miles