JetSetAuthority

Route · North Atlantic

SEA Seattle ⇄ LHR London

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

Distance7,702 km4,786 mi4,159 nautical miles
SEA → LHR9 h 25 minestimated block time
LHR → SEA10 h 10 minestimated block time
Clock change+7 hLondon vs Seattle, today
Great-circle route from Seattle (SEA) to London (LHR)SEASeattleLHRLondon
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 → LHR

9 h 25 min

Estimated gate-to-gate scheduled time. Initial heading 34° (NE).

Leave Seattle Sat 7 Nov, 10:00 local → arrive London Sun 8 Nov, 03:25 local +1 day.

LHR → SEA

10 h 10 min

Estimated gate-to-gate scheduled time. Initial heading 322° (NW).

Leave London Sat 7 Nov, 10:00 local → arrive Seattle Sat 7 Nov, 12:10 local.

SEA-bound flights are the slower direction by about 45 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 distance7,702 km · 4,786 mi · 4,159 nmi
Initial heading34° (NE) from SEA; 322° (NW) from LHR
Farthest from the equator67.5°N — the path arcs north of both airports
Crossesneither the equator nor the 180th meridian
Share of the longest possible trip38% 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
LHREurope/London — UTC+0 now; UTC+0 standard time, UTC+1 during daylight saving time
DifferenceLondon is 7 hours ahead of Seattle today.

Jet lag, flying SEA → LHR. 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 LHR London Heathrow AirportLondon, United Kingdom · longest runway 12,799 ft3,901 m

More routes from SEA and LHR

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 SEAKEF Seattle – Reykjavík 5,811 km3,611 mi · 7 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 LHRMAN London – Manchester 243 km151 mi · 1 h 20 min LHROSL London – Oslo 1,206 km749 mi · 2 h 20 min LHRTLV London – Tel Aviv 3,589 km2,230 mi · 4 h 50 min LHRANU London – St. John's 6,553 km4,072 mi · 9 h 05 min LHRSEZ London – Mahé 8,176 km5,080 mi · 10 h LHRSYD London – Sydney 17,021 km10,576 mi · 19 h 30 min

Routes of a similar length

GIGLIS Rio de Janeiro – Lisbon 7,715 km4,794 mi · 9 h 40 min JFKGRU New York – São Paulo 7,664 km4,762 mi · 9 h 35 min FRAPEK Frankfurt – Beijing 7,789 km4,840 mi · 9 h 20 min MANCUN Manchester – Cancún 7,794 km4,843 mi · 10 h 40 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).