The calculated distance (air line) between Sultanbeyli and Büyükçekmece is approximately 36 miles respectively 58 kilometers.
By car or train, the actual journey to Büyükçekmece is certainly longer, as only the direct route (as the crow flies) between Sultanbeyli and Büyükçekmece has been calculated here.
Air line (approximately)
58 kilometers
31 nautical miles