How Far Have You Actually Flown? Four Ways to Measure One Flight

Ask three sources how far it is from London to New York and you can get three different answers. A precise flight calculator says 5,555 km. A formula that treats the Earth as a perfect ball says 5,540. Your airline's loyalty statement may not show a distance at all, only miles earned against the fare you paid. And the aircraft itself flew none of those numbers: it climbed out on a departure procedure, followed its routing across the Atlantic, and joined an approach at the far end.

None of them is wrong. They measure different things. If you want a lifetime figure for how far you have flown, the useful question is not which number is true but which one you can calculate the same way for every flight you have ever taken. This piece sets out the four candidates, shows how far apart they sit on real routes, and ends with a method you can run in a spreadsheet tonight.

The short answer

Record every flight as a separate leg, measure each leg as the great-circle distance between its two airports, and add them up. Call the total a floor. Your aircraft flew further than that, usually by a few percent, and no record you can rebuild from boarding passes will tell you exactly how much.

Four distances for one flight

Measure	What it is	Who uses it
Great circle on a sphere	Shortest path over a perfectly round Earth	Most simple calculators and apps
Great circle on an ellipsoid	Shortest path over the Earth's real, slightly flattened shape	Surveyors and precise flight calculators
Ticketed point mileage	IATA's published distance between two ticketed points	Fare construction and airline accounting
Flown distance	The path the aircraft actually flew over the ground	Air navigation performance reports

The first two are geometry. The third is a commercial convention. The fourth is what happened, and it is the only one you cannot reconstruct afterwards.

Great-circle distance: the standard for good reason

A great-circle distance is the distance between two points on a sphere, measured along the arc of the great circle that joins them (Wikipedia). It is the shortest path over the surface, and it is how commercial aviation normally states the distance between two airports, because it depends only on the airports themselves and not on the weather or the routing on a particular day (Wikipedia).

That consistency is exactly what a personal record needs. The same city pair gives the same number every time you fly it, whether the flight was in 1998 or last Tuesday, and you can work it out from nothing more than the two airports' coordinates.

The usual formula is the haversine formula. It takes the latitude and longitude of both airports and an Earth radius, normally the mean radius of about 6,371 km, and it stays accurate even for very short distances, where the simpler spherical law of cosines suffers from rounding errors (Wikipedia).

Sphere or ellipsoid: a difference you can ignore

The Earth is not a perfect ball. It bulges at the equator, so any formula that assumes a sphere is an approximation, accurate to within about 0.5% (Wikipedia). The precise alternative is Vincenty's formulae, which work on the WGS84 ellipsoid and are accurate to within half a millimetre (Wikipedia).

We ran both methods on the same airport coordinates, taken from the reference list our own airport log uses:

Route	Sphere (haversine)	Ellipsoid (Vincenty)	Gap
London Heathrow to New York JFK	5,540 km	5,555 km	0.27%
London Heathrow to Los Angeles	8,760 km	8,781 km	0.24%
London Heathrow to Hong Kong	9,631 km	9,647 km	0.17%
Madrid to São Paulo Guarulhos	8,380 km	8,356 km	0.28%
New York JFK to Singapore	15,339 km	15,347 km	0.05%
London Heathrow to Edinburgh	534 km	535 km	0.12%

The sphere comes out short on the routes that run mostly east to west and long on Madrid to São Paulo, which crosses the equator on a long southward diagonal. The ellipsoid figure for New York to Singapore sits within two kilometres of the 15,349 km listed for Singapore Airlines' SQ23, the longest scheduled passenger flight by great-circle distance (Wikipedia), and the small remainder comes from which reference point at each airport you measure from.

The largest gap on these routes is under 0.3%, about 21 km across 8,800. Across a lifetime of flying that is noise. What matters is consistency: pick one method, use it for every leg, and last year's total stays comparable with this year's.

The distance your aircraft actually flew

Real flights do not follow the great circle. Aircraft fly set procedures out of and into airports, and the routing in between bends for weather, for winds, for airspace restrictions and for conflict-zone diversions (Wikipedia).

Europe measures part of that gap. EUROCONTROL's horizontal flight efficiency indicators compare the route flown with the great-circle distance between origin and destination (EUROCONTROL Aviation Intelligence Portal). The indicator for actual flights is the average additional distance flown over the great circle, and the EU's targets for it are 2.80% in 2025 and 2.75% in 2026 (EUROCONTROL Performance Review Report 2024). EUROCONTROL is clear that the figure cannot and should not reach zero, because some deviation is needed for separation between aircraft and to avoid danger areas (EUROCONTROL Aviation Intelligence Portal).

Two caveats keep that number in its place. It covers the en-route part of flights in European airspace, not the climb-out, the approach or a long-haul flight's whole route, so it gives you a sense of scale rather than a correction factor to multiply your total by. And the exact extra distance for any one flight exists only in that flight's recorded path, which you almost certainly do not have for a trip from ten years ago.

That is the practical case for recording great-circle distance and leaving the real figure alone. You can calculate the first for every flight you have ever taken. You cannot recover the second for most of them.

Why your airline's number is different again

Airlines keep their own distances, built for pricing rather than for measuring. IATA's Ticketed Point Mileage manual gives the distance covered by one flight coupon, calculated on the basis of non-stop or through scheduled services, for more than 65,000 city pairs, and it is used when calculating fares and when splitting revenue between airlines (IATA). It is a published table, not a measurement of the flight you took.

Loyalty statements sit further away still. Delta, for example, awards SkyMiles on its own flights by ticket price rather than distance flown: a general member earns 5 miles per dollar in Classic, and Delta Main Basic tickets earn none (Delta). Under a programme like that, the miles on your statement are a history of what you spent. A cheap long-haul fare can earn fewer miles than an expensive short hop, which is fine for a loyalty scheme and useless as a distance.

How to work out your lifetime distance

1. List every leg, one line each. A connection through Dubai is two legs, not one flight, and a return trip is at least two legs. Old boarding passes, confirmation emails and airline account histories are the sources, and our guide to logging travel history retroactively sets out where to look, cheapest source first.
2. Write the airport and the date, not just the code. Codes move between airports over time: HKG meant Kai Tak until 1998 and Chek Lap Kok ever since. IATA vs ICAO airport codes explains which code to write down and why the date matters.
3. Add each airport's latitude and longitude in decimal degrees. Any airport reference page lists them, and you only look each airport up once, however often you fly through it.
4. Calculate each leg. With the departure airport's latitude and longitude in B2 and C2, and the arrival airport's in D2 and E2, this formula gives the great-circle distance in kilometres in both Excel and Google Sheets:

=2*6371*ASIN(SQRT(SIN(RADIANS(D2-B2)/2)^2+COS(RADIANS(B2))*COS(RADIANS(D2))*SIN(RADIANS(E2-C2)/2)^2))

5. Change 6371 to 3959 if you want miles. It is the spherical method, so expect each result to sit within a fraction of a percent of a precise calculator, as the table above shows.
6. Sum the column, and label the total. "Great-circle distance, 2004 to 2026, 212 legs" still means something in ten years. A bare number does not.

For a sense of scale, the Earth's equator is 40,075 km round (NASA), or about two and a half New York to Singapore legs. The Moon averages 384,400 km away (NASA Space Place), which works out at roughly 35 return trips between London and New York.

What MapMyWorld's distance figure is, and isn't

The Stats page has a Distance Travelled card that splits a total into flights and ground, in miles or kilometres depending on your settings, and you can filter it by year and month. Here is exactly what it adds up, because it is not the lifetime figure described above.

• Flights are great circles on a sphere. Each leg uses the haversine formula with a 6,371 km radius, the same method as the spreadsheet formula. No route extension is added.
• A leg counts only when a departure airport is followed, in date order, by an arrival airport. Airports logged as a layover are left out of the calculation.
• Each airport appears once in your log. Six trips through Hong Kong make one Hong Kong entry, with one visit type and one date. So a route you fly repeatedly adds its distance once at most, and the flight home through an airport already in your log adds nothing. Someone who flew London to New York and back twice a year for five years has about 110,000 km of great-circle flying behind them. The card could show a single leg of 5,540 km.
• Ground distance is the straight line between your places in visit-date order, counting only hops shorter than 1,000 km, on the assumption that anything longer was a flight.
• The Free plan holds 10 airports, which limits how many legs the card can ever see. Pro removes the ceiling, at $7.99 a month, $59.99 a year or $199.99 once.

Read the flight figure as a lower bound built from the distinct airports in your log, not as the total distance you have flown. If the lifetime number matters to you, keep the leg list from the previous section alongside your record. It is the one version that counts every flight, and we would rather say so here than let a large number on a card imply more than it measures.

The rule on one card

• One line per leg, never per trip.
• Great-circle distance for every leg, calculated the same way each time.
• The airport's name and the date beside every code.
• Call the total a floor. Real flight paths run a few percent longer, and the exact figure is gone once the flight lands.
• Write down the method so the number still means something in ten years.

If you are building the airport list itself from scratch, how to log every airport you pass through covers the three fields that make each entry useful. The distance is one layer of the record. The airports, the dates and the trips beneath it are the rest. Start your record — free.