The calculated distance (air line) between Thanh Hóa and Thái Nguyên is approximately 124 miles respectively 200 kilometers.
By car or train, the actual journey to Thái Nguyên is certainly longer, as only the direct route (as the crow flies) between Thanh Hóa and Thái Nguyên has been calculated here.
Air line (approximately)
200 kilometers
108 nautical miles