Use this flight distance calculator to estimate the great-circle distance between two airports, the longer distance an aircraft is likely to fly in practice, and a rough gate-to-gate time. The estimate covers 1,148 airports with scheduled service and ignores wind.
Flight Distance Calculator
Enter two airports by IATA code, airport name or city.
Result summary
Great-circle distance is not the distance your flight covers
The great-circle distance is the shortest path between two points on a sphere. It is the number almost every flight distance tool reports, and no aircraft flies it. Routes bend around airways, restricted airspace, oceanic tracks and weather, and flights hold before landing.
The UK Greenhouse Gas Inventory handles this with a fixed correction. GOV.UK states that an 8% uplift factor is used to account for indirect flight paths and delays. This page shows both figures so you can see the gap.
London Heathrow to New York JFK is about 5,540 km great-circle, so the likely flown distance is about 5,983 km, roughly 443 km further than the shortest path. On Dubai to Singapore, about 5,846 km great-circle becomes about 6,314 km, a gap of around 468 km.
How the calculation works
Distance uses the haversine formula on a sphere of mean radius 6,371.0088 km, which is the arithmetic mean radius derived from the WGS-84 ellipsoid. Coordinates come from OurAirports and are rounded to three decimal places, or about 110 metres.
A spherical model is used rather than an ellipsoidal one on purpose, and the size of that choice has been measured. Across 3,989 airport pairs from this dataset, the spherical figure sits between 0.39% below and 0.54% above the WGS-84 geodesic, with a median of 0.09% below. That is an order of magnitude smaller than the 8% routing uplift, so ellipsoidal precision would be lost inside a larger correction.
It does mean this page can read slightly low against tools that use an ellipsoidal model. On London Heathrow to New York JFK the difference is about 15 km, or 5,540 km here against about 5,555 km elsewhere. On most routes the gap is far smaller.
The initial bearing is the compass heading at the point of departure. It changes continuously along a great-circle path, which is why a route that leaves London heading north west can arrive in New York heading south west.
Gate-to-gate time divides the flown distance by the cruise speed you select, then adds 30 minutes for taxi, climb and descent. Those speeds and that allowance are assumptions, not published figures for any specific aircraft.
Where the estimate breaks
Wind is the largest omission. Eastbound transatlantic flights ride the jet stream and westbound flights fight it, so the same route can differ by an hour or more depending on direction and season. This calculator applies no wind at all.
Taxi time varies by airport and time of day. A 30 minute allowance is generous at a quiet regional field and optimistic at a congested hub in a morning bank.
The airport list covers airports classified as large with scheduled service. Smaller regional fields are not included, so a code that fails to resolve is more likely missing than wrong.
Frequently asked questions
Why does my airline quote a different distance?
Airlines and loyalty programmes usually publish great-circle distance, because it is stable and easy to audit. The flown distance on the day depends on the routing air traffic control issues, and it is normally longer.
Is great-circle distance the same as flight distance?
No. Great-circle distance is the shortest theoretical path. Flight distance is what the aircraft actually covers, which this page estimates by adding the 8% uplift GOV.UK cites for indirect paths and delays.
Why is the eastbound flight quicker than the westbound one?
The jet stream flows west to east across the North Atlantic and North Pacific. Flying with it shortens the trip and flying against it lengthens it. This calculator reports the same time in both directions because it models no wind.
Which airports are included?
1,148 airports that OurAirports classifies as large and flags as having scheduled service, each with an IATA code. You can search by code, airport name or city.
Should I use this for fuel or emissions reporting?
Use it to sanity-check a figure, not to file one. For reporting, work from the current GOV.UK conversion factors and your own operator data rather than an estimate on a web page.
