The calculated distance (air line) between Gönen and Afyonkarahisar is approximately 55 miles respectively 89 kilometers.
By car or train, the actual journey to Afyonkarahisar is certainly longer, as only the direct route (as the crow flies) between Gönen and Afyonkarahisar has been calculated here.
Air line (approximately)
89 kilometers
48 nautical miles