The calculated distance (air line) between Reykjavík and Sauðárkrókur is approximately 129 miles respectively 208 kilometers.
By car or train, the actual journey to Sauðárkrókur is certainly longer, as only the direct route (as the crow flies) between Reykjavík and Sauðárkrókur has been calculated here.
Air line (approximately)
208 kilometers
112 nautical miles