The calculated distance (air line) between Sauðárkrókur and Kópavogur is approximately 131 miles respectively 211 kilometers.
By car or train, the actual journey to Kópavogur is certainly longer, as only the direct route (as the crow flies) between Sauðárkrókur and Kópavogur has been calculated here.
Air line (approximately)
211 kilometers
114 nautical miles