The calculated distance (air line) between Hilo and Napili-Honokowai is approximately 134 miles respectively 216 kilometers.
By car or train, the actual journey to Napili-Honokowai is certainly longer, as only the direct route (as the crow flies) between Hilo and Napili-Honokowai has been calculated here.
Air line (approximately)
216 kilometers
116 nautical miles