The calculated distance (air line) between Frasnes-lez-Buissenal and Mouscron is approximately 19 miles respectively 30 kilometers.
By car or train, the actual journey to Mouscron is certainly longer, as only the direct route (as the crow flies) between Frasnes-lez-Buissenal and Mouscron has been calculated here.
Air line (approximately)
30 kilometers
16 nautical miles