---
title: "London to Seattle (LHR → SEA): distance and flight time · Orbit"
description: "London to Seattle is 7,702 km (4,786 mi) great circle, an estimated 10h 04m in the air. The route, what it flies over, and why the short way is not the straight line on a map."
url: https://orbitflights.app/routes/lhr-to-sea
---

LHR → SEA

# London to Seattle: distance, flight time and the route it really takes

London Heathrow to Seattle–Tacoma is 7,702 km of great circle — 4,786 mi — and an estimated 10h 04m in the air. It crosses from Europe to North America.

**Great circle**
7,702 km
4,786 mi

**Estimated in the air**
10h 04m
block time

**Furthest from equator**
67.5°N
at 46% along

**One lap of Earth**
19.2%
of 40,075 km

Of the [292 routes catalogued here](https://orbitflights.app/routes), this is the 87th longest.

The London to Seattle route drawn as a great circle arc on a globe

## What the aircraft actually flies over

From London the path crosses United Kingdom, then 2,311 km of open water, then Greenland, then 443 km of open water, then Canada, then 558 km of open water, then Canada, then the United States.

The great circle reaches 67.5°N, inside the Arctic circle — which is why the route looks like a detour over the top of the world on a flat map, and like the obvious line on a globe.

Flying the line that looks straight on a Mercator map — one constant compass bearing — would cover 8,811 km. That is 1,109 km further, about 14% more, and roughly 1h 23m of extra flying.

Leaving London the aircraft points north-west (322°); it arrives into Seattle heading south-west (214°). That is 108° of drift without a single turn — the compass moves because the path is a curve on a sphere, not because the aircraft does.

One economy seat on it is about 1.09 t of CO₂e each way, counting non-CO₂ warming.

[LHR–SEA carbon footprint →](https://orbitflights.app/tools/flight-carbon-calculator?from=LHR&to=SEA) [Map this route →](https://orbitflights.app/tools/flight-route-map?r=LHR-SEA)

From

LHR

## London Heathrow

London, United Kingdom · Europe

51.5°N, 0.5°W

[LHR airport →](https://orbitflights.app/airports/lhr) [Flights to London →](https://orbitflights.app/flights-to/london)

To

SEA

## Seattle–Tacoma

Seattle, United States · North America

47.4°N, 122.3°W

[SEA airport →](https://orbitflights.app/airports/sea) [Flights to Seattle →](https://orbitflights.app/flights-to/seattle)

## London to Seattle, asked and answered

**How far is London to Seattle?**
London to Seattle (LHR to SEA) is 7,702 km, or 4,786 mi, measured as great circle distance between the two airports.

**How long is the flight from London to Seattle?**
About 10h 04m in the air. That is an estimate from the distance at a typical airliner block speed, plus half an hour for taxi, climb and descent; published schedules vary with winds and routing.

**What route does a London to Seattle flight take?**
The great circle passes over United Kingdom, then 2,311 km of open water, then Greenland, then 443 km of open water, then Canada, then 558 km of open water, then Canada, then the United States. It reaches 67.5°N at its furthest from the equator.

## Where these numbers come from

Distances are computed from the two airports’ own coordinates, not looked up from published routes. Times are estimates, not schedules.

[Why the shortest path is a curve →](https://orbitflights.app/blog/great-circle-routes-explained)

## Flown this one?

Orbit logs it in two taps and draws the arc on your own globe, along with every other flight you can remember. Free for your first 15.

[Download now](https://play.google.com/store/apps/details?id=com.qwertybit.orbit)

## Nearby routes

[SEA → HND Seattle to Tokyo 7,711 km](https://orbitflights.app/routes/sea-to-hnd) [LHR → DFW London to Dallas-Fort Worth 7,627 km](https://orbitflights.app/routes/lhr-to-dfw) [LHR → BLR London to Bangalore 8,046 km](https://orbitflights.app/routes/lhr-to-blr) [LHR → PEK London to Beijing 8,154 km](https://orbitflights.app/routes/lhr-to-pek) [LHR → BOM London to Mumbai 7,213 km](https://orbitflights.app/routes/lhr-to-bom) [LHR → MIA London to Miami 7,109 km](https://orbitflights.app/routes/lhr-to-mia)

## Further reading

[How many miles do you have to fly around the world?](https://orbitflights.app/blog/how-many-miles-to-fly-around-the-world) [What is on the exact opposite side of the world?](https://orbitflights.app/blog/opposite-side-of-the-world) [What's actually worth counting in a flight log](https://orbitflights.app/blog/what-is-worth-counting-in-a-flight-log)

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Markdown copy of https://orbitflights.app/routes/lhr-to-sea for language models and agents. Site index: https://orbitflights.app/llms.txt