The nonstop flight duration from Seattle (SEA) to London (all airports) is approximately 9 hours and 35 minutes. Other sources report similar times, with nonstop flights ranging from about 9 hours 20 minutes to 9 hours 45 minutes
. If including flights with stops, total travel time can be significantly longer, ranging from around 11 hours to over 30 hours depending on the number and length of stops
. A calculation based on average flight speed and distance estimates the flight time at about 10 hours and 5-6 minutes, which accounts for takeoff and landing time but may vary with wind and routing
. In summary, for a nonstop flight, expect roughly 9.5 to 10 hours of flight time from Seattle to London.
