Flight Distance Calculator
That's % of the way to the far side of the world.
This flight distance calculator measures the shortest path between two airports over the curve of the Earth, known as the great-circle distance. It's the number airlines and pilots start from, and the clean answer to "how far is it from here to there by air?" Type a city, airport name or three-letter code into each box.
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How Far Some Famous Routes Are
A few long and well-known city pairs, measured by the calculator above. Pick any route to load it.
| Route | Distance | Initial heading |
|---|---|---|
| New York (JFK) to Singapore (SIN) | 9,532 mi / 15,341 km / 8,283 nm | 3° (north) |
| London (LHR) to Sydney (SYD) | 10,576 mi / 17,021 km / 9,190 nm | 60° (east-northeast) |
| Doha (DOH) to Auckland (AKL) | 9,031 mi / 14,534 km / 7,848 nm | 118° (east-southeast) |
| Perth (PER) to London (LHR) | 9,015 mi / 14,508 km / 7,834 nm | 313° (northwest) |
| Los Angeles (LAX) to Singapore (SIN) | 8,762 mi / 14,102 km / 7,614 nm | 303° (west-northwest) |
| Johannesburg (JNB) to Atlanta (ATL) | 8,440 mi / 13,583 km / 7,334 nm | 295° (west-northwest) |
| Istanbul (IST) to Los Angeles (LAX) | 6,836 mi / 11,002 km / 5,940 nm | 333° (north-northwest) |
| Chicago (ORD) to Tokyo (HND) | 6,291 mi / 10,124 km / 5,466 nm | 323° (northwest) |
| Madrid (MAD) to Buenos Aires (EZE) | 6,267 mi / 10,087 km / 5,446 nm | 222° (southwest) |
| Paris (CDG) to Tokyo (HND) | 6,032 mi / 9,708 km / 5,242 nm | 34° (north-northeast) |
| São Paulo (GRU) to London (LHR) | 5,878 mi / 9,460 km / 5,108 nm | 27° (north-northeast) |
| Frankfurt am Main (FRA) to San Francisco (SFO) | 5,685 mi / 9,149 km / 4,940 nm | 323° (northwest) |
How This Is Calculated
The calculator uses each airport's published coordinates and the haversine formula, which treats the Earth as a sphere with a mean radius of 6,371 km (3,440 nautical miles). The real Earth bulges slightly at the equator, so the result is usually within half a percent of a more exact ellipsoid calculation.
A nautical mile is exactly 1,852 meters, a little longer than a statute mile. It's the unit pilots and air traffic controllers use for distance, and it started life as one minute of latitude, which is why it fits navigation so well.
The heading is the initial true course, measured clockwise from true north. On a great circle that heading changes as the plane flies, which is why a flight from New York to Singapore sets off almost due north, over the Arctic, before it ever turns south. Why planes don't fly straight explains the geometry.
Real flights follow airways and get routed around weather and restricted airspace, so the distance actually flown is longer than this. Treat the number above as the shortest possible distance.
Questions People Ask
How do you calculate the distance between two airports?
It's the great-circle distance: the shortest path between the two airports' coordinates over the curve of the Earth. The calculator works it out with the haversine formula on a sphere with a mean radius of 6,371 km, which is usually within half a percent of a more exact calculation.
Is flight distance the same as driving distance?
No. Flight distance here is a straight line over the curve of the Earth. Roads wind around terrain, water and borders, so the driving distance between two cities is almost always longer.
Why does my airline show a longer distance?
Airlines may quote the distance actually flown, which follows published airways and detours around weather and restricted airspace. The great-circle figure here is the shortest possible distance, so real numbers usually come out a little higher.
What is a nautical mile?
Exactly 1,852 meters, or about 1.15 statute miles. It began as one minute of latitude, and it's the unit pilots and air traffic controllers use for distance and, as knots, for speed.
What does the initial heading mean?
It's the compass direction, measured clockwise from true north, that a plane would set off on to follow the great circle. The heading changes along the way, so a long flight can start out heading north and end up flying south.
What's the farthest apart two airports can be?
Two points on exactly opposite sides of the Earth are about 12,437 miles (20,015 km, or 10,807 nautical miles) apart along the surface: half the planet's circumference. That's the 100 percent mark the calculator measures each route against.