The calculated distance (air line) between Pistoia and Castelfranco di Sotto is approximately 18 miles respectively 29 kilometers.
By car or train, the actual journey to Castelfranco di Sotto is certainly longer, as only the direct route (as the crow flies) between Pistoia and Castelfranco di Sotto has been calculated here.
Air line (approximately)
29 kilometers
16 nautical miles