The calculated distance (air line) between Bochum-Hordel and Zaventem is approximately 125 miles respectively 200 kilometers.
By car or train, the actual journey to Zaventem is certainly longer, as only the direct route (as the crow flies) between Bochum-Hordel and Zaventem has been calculated here.
Air line (approximately)
200 kilometers
108 nautical miles