The calculated distance (air line) between Phetchaburi and Nakhon Sawan is approximately 180 miles respectively 289 kilometers.
By car or train, the actual journey to Nakhon Sawan is certainly longer, as only the direct route (as the crow flies) between Phetchaburi and Nakhon Sawan has been calculated here.
Air line (approximately)
289 kilometers
156 nautical miles