London (LHR) – Seattle (SEA)
- Distance
- 7,725 km
- 4,800 mi · 4,171 nm
- Flight time
- 10 h 5 min / 9 h 34 min
- Average gate to gate: LHR → SEA / back
- Time difference
- 8 h
- CO2 per passenger
- 901 kg
- One way, economy, incl. RF (533 kg CO2 only)
- Passengers / year
- 563,864
- Aug 2025 – Jul 2026 · +7.1%
- Flights / week
- 52
- Both directions, average
- Seats filled
- 81%
- 695,460 seats a year
- Airlines nonstop
- 4
- BA, DL, VS
Traffic: U.S. DOT, Bureau of Transportation Statistics, T-100 Segment (all carriers, scheduled service), Aug 2025 – Jul 2026. Distance: WGS-84 ellipsoid. CO2: UK DESNZ 2026 factors. Sources
The way there
- Heading from LHR
- 322°
- Heading from SEA
- 34°
- Halfway point
- 67.40, -65.60
- Great-circle km
- 7,702 km (sphere, for EU261)
- In the air LHR → SEA
- 9 h 25 min
- In the air SEA → LHR
- 9 h 2 min
- Clocks
- Seattle is 8 h behind London
The estimate for a route without real times is 9 h 55 min; how it is worked out is on Sources.
Show as a table
| Month | Passengers |
|---|---|
| Aug 2025 | 59,499 |
| Sep 2025 | 56,028 |
| Oct 2025 | 46,103 |
| Nov 2025 | 32,836 |
| Dec 2025 | 37,134 |
| Jan 2026 | 33,458 |
| Feb 2026 | 28,686 |
| Mar 2026 | 37,597 |
| Apr 2026 | 43,579 |
| May 2026 | 55,164 |
| Jun 2026 | 64,021 |
| Jul 2026 | 69,759 |
Show as a table
| Month | Flights |
|---|---|
| Aug 2025 | 247 |
| Sep 2025 | 239 |
| Oct 2025 | 233 |
| Nov 2025 | 177 |
| Dec 2025 | 184 |
| Jan 2026 | 185 |
| Feb 2026 | 162 |
| Mar 2026 | 187 |
| Apr 2026 | 223 |
| May 2026 | 269 |
| Jun 2026 | 293 |
| Jul 2026 | 304 |
Airlines flying LHR–SEA nonstop
| Airline | Flights / week | Share of passengers |
|---|---|---|
| BABritish Airways | 24 | 49% |
| DLDelta Air Lines | 14 | 25% |
| VSVirgin Atlantic Airways | 11 | 20% |
| ASAlaska Airlines | 2.8 | 6% |
Both directions, Aug 2025 – Jul 2026. Airlines with at least one flight a month. U.S. DOT, Bureau of Transportation Statistics, T-100 Segment (all carriers, scheduled service). Sources
Aircraft on this route
- Boeing 787-10 Dreamliner · 534 flights
- Boeing 777-300/300ER/333ER · 467 flights
- Airbus Industrie A330-900 · 425 flights
- Airbus A330-900neo · 410 flights
- B787-900 Dreamliner · 396 flights
- Airbus Industrie A330-200 · 295 flights
- Boeing 777-200ER/200LR/233LR · 166 flights
- Airbus Industrie A330-300/333 · 10 flights
Also carried: 10,999 tonnes of freight and 0 tonnes of mail a year (passenger and cargo flights).
Delay compensation (EU261 / UK261)
Measured by great-circle distance: 7,702 km.
LHR London → SEA Seattle
UK261£520 for arriving 3 hours or more late (£260 if 3–4 hours).
Covers any airline.
SEA Seattle → LHR London
UK261£520 for arriving 3 hours or more late (£260 if 3–4 hours).
Covers UK or EU airlines only.
Also owed for a cancellation with less than 14 days' notice or denied boarding. Not owed for extraordinary circumstances. On a connection, the distance to the final destination counts. From 23 October 2027 the EU's Regulation 2026/2202 applies; it keeps these amounts (what changes in 2027). Information, not legal advice.
Every airport pair between London and Seattle
Kilometres. Linked numbers have a page of their own. All London airports · All Seattle airports
More routes from LHR
More routes from SEA
| Route | Distance | Passengers / year |
|---|---|---|
| SEA → DEN | 1,648 km | 1,819,437 |
| SEA → PHX | 1,781 km | 1,813,338 |
| SEA → LAX | 1,535 km | 1,810,795 |
| SEA → ANC | 2,331 km | 1,694,688 |
| SEA → SFO | 1,092 km | 1,628,228 |
| SEA → ORD | 2,769 km | 1,622,991 |
| SEA → LAS | 1,394 km | 1,596,435 |
| SEA → DFW | 2,671 km | 1,577,921 |
| SEA → SAN | 1,690 km | 1,233,726 |
| SEA → SLC | 1,108 km | 1,106,553 |