✈ SEA → LHR
9H 55M FLIGHT. TWO MOVIES, NO SLEEP, ONE EXISTENTIAL CRISIS.
Flight from Seattle to London
From Sea-Tac (SEA), USA North America → Heathrow (LHR), United Kingdom Europe
How long is the flight from Seattle to London?
A nonstop flight from Seattle (SEA) to London (LHR) takes about 9 hours 55 minutes, covering a great-circle distance of 4,786 miles (7,702 km). Actual scheduled time varies by airline, routing, and wind — expect ±15 to 30 minutes from this estimate.
Avg flight time
9h 55m
Nonstop, scheduled
Distance
4,786 mi
7,702 km · great-circle
Avg speed
776 km/h
Door-to-door including taxi
Time zones & jet lag
Seattle timezone
UTC-7
America/Los_Angeles
London timezone
UTC+1
Europe/London
Time difference
+8h
8 hours ahead
Jet lag (rough)
~8d
Eastward — worse
CO₂ footprint per passenger
Economy class, single passenger. Source: DEFRA 2024 averages.
This flight emits roughly 3.6× the CO₂ of an equivalent train trip and 0.9× a car driven alone over the same distance.