The calculated distance (air line) between Bochum-Hordel and Houthalen is approximately 84 miles respectively 136 kilometers.
By car or train, the actual journey to Houthalen is certainly longer, as only the direct route (as the crow flies) between Bochum-Hordel and Houthalen has been calculated here.
Air line (approximately)
136 kilometers
73 nautical miles