The calculated distance (air line) between Vĩnh Yên and Dien Bien Phu is approximately 166 miles respectively 268 kilometers.
By car or train, the actual journey to Dien Bien Phu is certainly longer, as only the direct route (as the crow flies) between Vĩnh Yên and Dien Bien Phu has been calculated here.
Air line (approximately)
268 kilometers
144 nautical miles