The calculated distance (air line) between Piranshahr and Ḩalabja is approximately 115 miles respectively 186 kilometers.
By car or train, the actual journey to Ḩalabja is certainly longer, as only the direct route (as the crow flies) between Piranshahr and Ḩalabja has been calculated here.
Air line (approximately)
186 kilometers
100 nautical miles