The calculated distance (air line) between Quỳnh Lôi and Thái Nguyên is approximately 42 miles respectively 68 kilometers.
By car or train, the actual journey to Thái Nguyên is certainly longer, as only the direct route (as the crow flies) between Quỳnh Lôi and Thái Nguyên has been calculated here.
Air line (approximately)
68 kilometers
37 nautical miles