To work out how far you've flown, list every flight you've taken by its departure and arrival airports, find the great-circle distance of each (the shortest path between two points over the Earth's surface), and add them up. One way from London Heathrow to New York JFK is about 5,540 km (3,440 miles), so a single round trip is roughly 11,080 km. Divide your total by 40,075 km, the Earth's circumference at the equator, and you get your laps of the planet.
The rest of this guide explains each step, with real routes to check your numbers against.
What great-circle distance is
The Earth is (very nearly) a sphere, and the shortest path between two points on a sphere is an arc of a "great circle," a circle whose center is the center of the Earth. The equator is one, and so is any circle that runs through both poles.
On a flat world map, these shortest paths look curved, and often surprisingly far north. The great-circle path from New York to Tokyo bends up over Alaska. The one from Los Angeles to Dubai passes within about 600 km of the North Pole. On a globe, a string pulled tight between the two airports follows the same path.
Great-circle distance is the standard way to measure a flight, because it depends only on the two airports. It's the same whichever airline you flew or whatever the weather was.
How to calculate it
You need the latitude and longitude of both airports and the Earth's radius. The usual method is the haversine formula, which works out the angle between the two points as seen from the Earth's center, then multiplies it by the radius. Using NASA's mean radius of 6,371 km gives distances accurate enough for any travel log.
You don't need to do the math yourself. Our flight distance calculator takes two airports and gives the great-circle distance between them.
Some real routes to compare
| Route | Great-circle distance |
|---|---|
| London Heathrow (LHR) to New York JFK | about 5,540 km (3,440 miles) |
| Frankfurt (FRA) to Chicago O'Hare (ORD) | about 6,970 km (4,330 miles) |
| London Heathrow (LHR) to Singapore (SIN) | about 10,880 km (6,760 miles) |
| Sydney (SYD) to Los Angeles (LAX) | about 12,060 km (7,490 miles) |
| New York JFK to Singapore (SIN) | about 15,340 km (9,530 miles) |
Any of the last three is enough for the bucket-list line travel more than 8,000 km in one hop.
Why the plane flew further than that
The distance you actually traveled in the air is a little longer than the great circle. Planes follow set airways rather than a perfect arc, steer around weather and closed airspace, ride or dodge the jet stream, and sometimes circle before landing. Airlines publish flight times, not flown distances, so great-circle distance is the fair, repeatable number to add up. Just know your real total is somewhat higher.
Step by step: your total
- Make a list of every flight. One row per takeoff and landing, with the two airport codes. A trip via a hub is two flights. How to make a log of every flight you've taken shows where to find old ones.
- Look up each distance. Use the flight distance calculator for each pair of airports, and write the result in its own column.
- Add up the column. A spreadsheet's SUM does it in one go. Keep kilometers and miles in separate columns if you want both.
- Count the extras. While you're there, count your unique airports, your flights, and your longest single flight.
Return trips are two flights. It's easy to log "London–New York" once and forget you came back.
Putting your number in perspective
Big totals are hard to picture, so travelers turn them into laps and trips to the Moon:
- Laps of the Earth. NASA gives the Earth's equatorial radius as 6,378.137 km, which makes the equator about 40,075 km (24,900 miles) around. Divide your total by 40,075.
- The Moon. The average distance from the Earth to the Moon is about 384,400 km (238,900 miles), from NASA's Moon fact sheet.
An example: someone who has flown London to New York 20 times one way (ten round trips) has covered about 110,800 km. That's about 2.8 laps of the Earth, and just over a quarter of the way to the Moon.
Globestamp keeps this tally for you: import a flight log and it shows your flights, kilometers, hours, airports and laps of the Earth, with the whole flight log in Pro.
Hours in the air
Distance is one measure; time is another. Your booking emails and boarding passes show scheduled times. Add up the scheduled duration of each flight for a reasonable total, remembering to allow for time zones: a flight that leaves at 10:00 and lands at 13:00 local time may have taken eight hours.
Countries you only flew through
A long log will include airports in countries you never left the terminal of. Those are worth noting, but whether they count as countries you've visited is a separate question. Does a layover count as visiting a country? goes through the arguments. To see how your countries add up, how to count the countries you've visited is the place to start.