The calculated distance (air line) between Bochum-Hordel and Gießen is approximately 91 miles respectively 146 kilometers.
By car or train, the actual journey to Gießen is certainly longer, as only the direct route (as the crow flies) between Bochum-Hordel and Gießen has been calculated here.
Air line (approximately)
146 kilometers
79 nautical miles