---
title: "Houston to Sydney (IAH → SYD): distance and flight time · Orbit"
description: "Houston to Sydney is 13,836 km (8,597 mi) great circle, an estimated 17h 42m 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/iah-to-syd
---

IAH → SYD

# Houston to Sydney: distance, flight time and the route it really takes

George Bush Intercontinental to Sydney Kingsford Smith is 13,836 km of great circle — 8,597 mi — and an estimated 17h 42m in the air. It crosses from North America to Oceania.

**Great circle**
13,836 km
8,597 mi

**Estimated in the air**
17h 42m
block time

**Furthest from equator**
33.9°S
at 100% along

**One lap of Earth**
34.5%
of 40,075 km

Of the [292 routes catalogued here](https://orbitflights.app/routes), this is the 12th longest.

The Houston to Sydney route drawn as a great circle arc on a globe

## What the aircraft actually flies over

From Houston the path crosses the United States, then Mexico, then 12,176 km of open water.

The furthest the great circle gets from the equator is 33.9°S, 100% of the way along.

Flying the line that looks straight on a Mercator map — one constant compass bearing — would cover 13,893 km. That is 57 km further, about 0% more, and roughly 4m of extra flying.

Leaving Houston the aircraft points south-west (247°); it arrives into Sydney heading west (254°). That is 7° 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 1.96 t of CO₂e each way, counting non-CO₂ warming.

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

From

IAH

## George Bush Intercontinental

Houston, United States · North America

30.0°N, 95.3°W

[IAH airport →](https://orbitflights.app/airports/iah)

To

SYD

## Sydney Kingsford Smith

Sydney, Australia · Oceania

33.9°S, 151.2°E

[SYD airport →](https://orbitflights.app/airports/syd) [Flights to Sydney →](https://orbitflights.app/flights-to/sydney)

## Houston to Sydney, asked and answered

**How far is Houston to Sydney?**
Houston to Sydney (IAH to SYD) is 13,836 km, or 8,597 mi, measured as great circle distance between the two airports.

**How long is the flight from Houston to Sydney?**
About 17h 42m 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 Houston to Sydney flight take?**
The great circle passes over the United States, then Mexico, then 12,176 km of open water. It reaches 33.9°S 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

[DFW → SYD Dallas-Fort Worth to Sydney 13,808 km](https://orbitflights.app/routes/dfw-to-syd) [SYD → DFW Sydney to Dallas-Fort Worth 13,808 km](https://orbitflights.app/routes/syd-to-dfw) [YVR → SYD Vancouver to Sydney 12,501 km](https://orbitflights.app/routes/yvr-to-syd) [LAX → SYD Los Angeles to Sydney 12,061 km](https://orbitflights.app/routes/lax-to-syd) [EZE → SYD Buenos Aires to Sydney 11,767 km](https://orbitflights.app/routes/eze-to-syd) [SCL → SYD Santiago to Sydney 11,340 km](https://orbitflights.app/routes/scl-to-syd)

## 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/iah-to-syd for language models and agents. Site index: https://orbitflights.app/llms.txt