The calculated distance (air line) between Luang Prabang and Ban Houakhoua is approximately 113 miles respectively 182 kilometers.
By car or train, the actual journey to Ban Houakhoua is certainly longer, as only the direct route (as the crow flies) between Luang Prabang and Ban Houakhoua has been calculated here.
Air line (approximately)
182 kilometers
98 nautical miles