The calculated distance (air line) between Bonn and Schwäbisch Gmünd is approximately 180 miles respectively 290 kilometers.
By car or train, the actual journey to Schwäbisch Gmünd is certainly longer, as only the direct route (as the crow flies) between Bonn and Schwäbisch Gmünd has been calculated here.
Air line (approximately)
290 kilometers
156 nautical miles