The calculated distance (air line) between Sauðárkrókur and Garðabær is approximately 133 miles respectively 213 kilometers.
By car or train, the actual journey to Garðabær is certainly longer, as only the direct route (as the crow flies) between Sauðárkrókur and Garðabær has been calculated here.
Air line (approximately)
213 kilometers
115 nautical miles