Skip to content

Flight Distance Calculator

TravelFlights and Air Travel
Departure
Arrival
Great-circle distance (km) —
Statute miles
—
Nautical miles
—
Initial heading (° from true north)
—
Rough flight time
—

Flight distance is measured along the great circle, the shortest path over the Earth's surface. The haversine formula on a sphere of radius 6,371 km gives New York JFK to London Heathrow as about 5,540 km (3,442 mi, 2,991 nmi), leaving New York on an initial heading of 51.4°. Actual flown tracks run a few percent longer because of airways and winds.

About this tool

Frequent flyers checking mileage credit, pilots sketching a route, and students working spherical geometry all need the same number: how far apart two points are over a curved Earth. Pick a departure and arrival from the list of 26 busy hubs, or choose Other to type latitude and longitude for any airfield. The result shows the great-circle distance in kilometres, statute miles and nautical miles, the initial true heading at departure, and a rough flight time based on an 850 km/h cruise plus half an hour for taxi, climb and descent. The working is listed line by line so the figure can be checked by hand. One limit: the calculation assumes a sphere, so it can differ from an ellipsoidal (WGS-84) result by up to about 0.5 percent, and it ignores the extra distance of real air routes.

How to use it

  1. Pick the departure airport

    Choose from the list, or select Other (coordinates) to enter latitude and longitude in decimal degrees.

  2. Pick the arrival airport

    Same list. West longitudes and south latitudes are negative numbers.

  3. Read the distance and heading

    Kilometres are the headline; miles, nautical miles, initial heading and a rough flight time follow, with the haversine working underneath.

Examples

New York JFK to London Heathrow

From
New York JFK
To
London Heathrow

Result Great-circle distance (km): 5,540
Statute miles: 3,442
Nautical miles: 2,991
Initial heading (° from true north): 51.4
Rough flight time: 7 h 1 min

  1. From JFK (40.6413°, -73.7781°) to LHR (51.47°, -0.4543°)
  2. a = sin²(Δφ/2) + cos φ1 · cos φ2 · sin²(Δλ/2) = 0.177421
  3. c = 2 · atan2(√a, √(1−a)) = 0.869567 rad
  4. d = 6371.0088 km × c = 5540 km = 3442.4 mi = 2991.4 nmi
  5. Rough flight time = d ÷ 850 km/h + 30 min taxi, climb and descent = 7.02 h

The great circle leaves New York heading north-east at about 51° and arcs up past Newfoundland and Ireland, which is why the transatlantic track looks curved on a flat map.

Dubai to Sydney

From
Dubai DXB
To
Sydney SYD

Result Great-circle distance (km): 12,043
Statute miles: 7,483
Nautical miles: 6,503
Initial heading (° from true north): 119.6
Rough flight time: 14 h 40 min

  1. From DXB (25.2532°, 55.3657°) to SYD (-33.9399°, 151.1753°)
  2. a = sin²(Δφ/2) + cos φ1 · cos φ2 · sin²(Δλ/2) = 0.657071
  3. c = 2 · atan2(√a, √(1−a)) = 1.89035 rad
  4. d = 6371.0088 km × c = 12043.4 km = 7483.4 mi = 6502.9 nmi
  5. Rough flight time = d ÷ 850 km/h + 30 min taxi, climb and descent = 14.67 h

One of the longer nonstop routes in service; the scheduled block time is close to the rough estimate because the cruise leg dominates.

Custom coordinates: 0°, 0° to 0°, 90°

From
Other (coordinates)
Departure latitude
0
Departure longitude
0
To
Other (coordinates)
Arrival latitude
0
Arrival longitude
90

Result Great-circle distance (km): 10,008
Statute miles: 6,218
Nautical miles: 5,404
Initial heading (° from true north): 90
Rough flight time: 12 h 16 min

  1. From 0, 0 (0°, 0°) to 0, 90 (0°, 90°)
  2. a = sin²(Δφ/2) + cos φ1 · cos φ2 · sin²(Δλ/2) = 0.5
  3. c = 2 · atan2(√a, √(1−a)) = 1.570796 rad
  4. d = 6371.0088 km × c = 10007.6 km = 6218.4 mi = 5403.6 nmi
  5. Rough flight time = d ÷ 850 km/h + 30 min taxi, climb and descent = 12.27 h

A quarter of the equator on the mean sphere, π/2 × 6371.0088 km, a handy check of the method.

How it is calculated

a = sin²(Δφ/2) + cos φ1 · cos φ2 · sin²(Δλ/2); c = 2 · atan2(√a, √(1 − a)); d = R · c

φ1, φ2
latitudes of departure and arrival, in radians
Δλ
difference in longitude, in radians
R
mean Earth radius, 6,371.0088 km
d
great-circle distance

The haversine form stays numerically stable for short hops as well as near-antipodal routes. Kilometres are converted with 1 mi = 1.609344 km and 1 nmi = 1.852 km exactly. The initial heading is atan2(sin Δλ · cos φ2, cos φ1 · sin φ2 − sin φ1 · cos φ2 · cos Δλ), normalised to 0–360°. Flight time is d ÷ 850 km/h plus 30 minutes, a planning rule of thumb rather than a schedule.

When not to use it

  • Do not use it for flight planning fuel figures; those need the filed route, winds and aircraft performance.
  • Survey or geodesy work needs an ellipsoidal (Vincenty or Karney) distance, not a spherical one.
  • Airline loyalty programmes may use their own published mileage tables that differ slightly.

Common mistakes

  • Entering a western longitude as positive puts the point on the other side of the world.
  • Typing degrees-minutes like 40.38 for 40°38′ instead of the decimal 40.6333.
  • Expecting the heading to stay constant; on a great circle it changes along the way.
  • Comparing with a straight line drawn on a Mercator map, which looks longer or bent.

Frequently asked questions

Why does the shortest route look curved on a map?

Flat maps such as the Mercator projection stretch high latitudes. The great circle between New York and London bends north on such a map, yet it is the shortest path on the globe. On a globe it would look like a straight band.

How far is one degree of latitude?

On the mean sphere used here, one degree of arc is 2π × 6,371.0088 ÷ 360 ≈ 111.2 km, or about 60 nautical miles. That near-match is why the nautical mile was historically defined as one minute of arc.

How close is the spherical result to the true ellipsoidal distance?

The Earth is slightly flattened at the poles, so a spherical distance can be off by up to roughly 0.5 percent compared with a WGS-84 ellipsoid calculation. For a 5,000 km trip that is up to about 25 km, which is negligible for travel planning.

Why is my airline's flown distance longer?

Aircraft follow airways, organised tracks and wind-optimised routes, and they climb and descend away from the direct line. Flown distances are commonly a few percent longer than the great circle, more on congested or politically restricted routes.

What does the initial heading mean?

It is the true course, measured clockwise from geographic north, at the moment of departure along the great circle. Because a great circle crosses meridians at changing angles, the heading drifts during the flight except on the equator or due north–south routes.

How is the rough flight time estimated?

Distance divided by an 850 km/h typical jet cruise speed, plus 30 minutes for taxi, climb and approach. Headwinds on westbound transatlantic flights can add an hour; scheduled times also include buffer, so treat it as a ballpark.

Can I use an airport that is not in the list?

Yes. Choose Other (coordinates) and enter the airfield's latitude and longitude in decimal degrees, which are published on airport pages and aeronautical charts. Use negative values for south and west.

Cite this tool

Using this tool in an assignment, article or report? Copy a citation, or a link for your website.

APA

Tools Directory Editorial Team. (2026, October 19). Flight Distance Calculator. Tools Directory. Retrieved October 25, 2026, from https://tools.milunir.com/travel/flights-and-air-travel/flight-distance-calculator/

MLA

Tools Directory Editorial Team. “Flight Distance Calculator.” Tools Directory, 19 Oct. 2026, https://tools.milunir.com/travel/flights-and-air-travel/flight-distance-calculator/. Accessed 25 Oct. 2026.

Chicago

Tools Directory Editorial Team. “Flight Distance Calculator.” Tools Directory. Last modified October 19, 2026. Accessed October 25, 2026. https://tools.milunir.com/travel/flights-and-air-travel/flight-distance-calculator/.

Link<a href="https://tools.milunir.com/travel/flights-and-air-travel/flight-distance-calculator/">Flight Distance Calculator – Tools Directory</a>