JetSetAuthority

Route · North Atlantic

SEA Seattle ⇄ KEF Reykjavík

Seattle–Tacoma International Airport (United States) and Keflavik International Airport (Iceland): great-circle distance, estimated scheduled flight time each way, time difference and jet lag.

Distance5,811 km3,611 mi3,138 nautical miles
SEA → KEF7 h 25 minestimated block time
KEF → SEA7 h 55 minestimated block time
Clock change+7 hReykjavík vs Seattle, today
Great-circle route from Seattle (SEA) to Reykjavík (KEF)SEASeattleKEFReykjavík
The shortest path over the Earth’s surface (great circle), drawn on a Natural Earth projection. Real flight paths bend around weather, winds and closed airspace.

Flight time each way

SEA → KEF

7 h 25 min

Estimated gate-to-gate scheduled time. Initial heading 33° (NNE).

Leave Seattle Sat 7 Nov, 10:00 local → arrive Reykjavík Sun 8 Nov, 01:25 local +1 day.

KEF → SEA

7 h 55 min

Estimated gate-to-gate scheduled time. Initial heading 303° (WNW).

Leave Reykjavík Sat 7 Nov, 10:00 local → arrive Seattle Sat 7 Nov, 09:55 local.

SEA-bound flights are the slower direction by about 30 minutes in our estimate: the route runs partly east–west through latitudes where the prevailing westerly winds at cruise height are strong, so heading east rides a tailwind and heading west fights a headwind. How we estimate it.

Distance

Great-circle distance5,811 km · 3,611 mi · 3,138 nmi
Initial heading33° (NNE) from SEA; 303° (WNW) from KEF
Farthest from the equator68.3°N — the path arcs north of both airports
Crossesneither the equator nor the 180th meridian
Share of the longest possible trip29% of the 20,015 km to the far side of the Earth

Time zones and jet lag

SEAAmerica/Los_Angeles — UTC−7 now; UTC−8 standard time, UTC−7 during daylight saving time
KEFAtlantic/Reykjavik — UTC+0 now; UTC+0 all year (no daylight saving time)
DifferenceReykjavík is 7 hours ahead of Seattle today; +8 h in January and +7 h in July because daylight saving time starts and ends on different dates (or not at all).

Jet lag, flying SEA → KEF. Your body clock has to move 7 hours earlier, like an eastward trip. A common rule of thumb is that the body clock adjusts by roughly one time zone a day, so expect up to about 7 days to fully adjust. Shifting earlier (as here) is usually the harder direction; morning daylight at the destination helps. Flying the other way, the shift is reversed.

General information, not medical advice.

The two airports

SEA Seattle–Tacoma International AirportSeattle, United States · longest runway 11,901 ft3,627 m KEF Keflavik International AirportReykjavík, Iceland · longest runway 10,056 ft3,065 m

More routes from SEA and KEF

SFOSEA San Francisco – Seattle 1,093 km679 mi · 2 h 20 min SEADEN Seattle – Denver 1,645 km1,022 mi · 2 h 45 min SEAORD Seattle – Chicago 2,762 km1,716 mi · 3 h 55 min SEALHR Seattle – London 7,702 km4,786 mi · 9 h 25 min SEAAMS Seattle – Amsterdam 7,840 km4,872 mi · 9 h 40 min SINSEA Singapore – Seattle 12,979 km8,065 mi · 15 h LHRKEF London – Reykjavík 1,895 km1,178 mi · 3 h 20 min KEFCPH Reykjavík – Copenhagen 2,144 km1,332 mi · 3 h 25 min BOSKEF Boston – Reykjavík 3,875 km2,408 mi · 5 h 15 min JFKKEF New York – Reykjavík 4,163 km2,587 mi · 5 h 30 min

Routes of a similar length

CMNJFK Casablanca – New York 5,795 km3,601 mi · 8 h 25 min JFKCDG New York – Paris 5,834 km3,625 mi · 7 h 10 min DXBSIN Dubai – Singapore 5,846 km3,632 mi · 7 h 30 min JFKAMS New York – Amsterdam 5,848 km3,634 mi · 7 h 10 min

Need a different pair? The flight-time calculator works for any two of 3,245 airports. Not covered: which airlines fly this route, schedules, fares and live status — that data is proprietary and we don’t guess it.

Photos on airport pages are credited there. Estimates are rounded to 5 minutes; typical error about 13 minutes (validation).