The calculated distance (air line) between Reykjavík and Ísafjörður is approximately 139 miles respectively 223 kilometers.
By car or train, the actual journey to Ísafjörður is certainly longer, as only the direct route (as the crow flies) between Reykjavík and Ísafjörður has been calculated here.
Air line (approximately)
223 kilometers
120 nautical miles