What is a great-circle route?

A great-circle route is the shortest path between two points on the surface of a sphere. On the Earth, it corresponds to the intersection of the sphere with a plane passing through both points and the center of the Earth. Aircraft follow great-circle routes on long flights to minimize distance and fuel burn.

What is the Haversine formula?

The Haversine formula is a well-known equation in navigation that calculates the shortest distance between two points on a sphere given their latitudes and longitudes. It is numerically stable for small distances, making it the standard choice for aviation and geodetic calculations.

How do I enter coordinates?

Enter decimal degrees. Use positive values for North latitude and East longitude; use negative values for South latitude and West longitude. For example, Los Angeles International Airport is approximately 33.9425° N, 118.4081° W — enter 33.9425 and -118.4081.

What is the initial bearing?

The initial bearing is the true course (compass heading, ignoring magnetic variation) you would fly at the moment of departure to follow the great-circle route. Because the Earth is curved, this bearing changes continuously along the route.

How accurate is this calculator?

The Haversine formula assumes a perfectly spherical Earth with a radius of 6,371 km. Real Earth distances can differ by up to 0.5% due to the oblateness of the geoid. For operational flight planning always use certified software and charts.

What is the difference between great-circle and rhumb-line distance?

A rhumb line (loxodrome) follows a constant compass bearing, making it easier to fly manually, but it is longer than the great-circle route except on short legs or along meridians. For transcontinental or transoceanic flights the great-circle route can save hundreds of miles.

Great Circle Route Calculator

Name: Great Circle Route Calculator
Availability: InStock
Author: Nham Vu

Enter two sets of latitude/longitude coordinates to get the great-circle distance and initial bearing using the Haversine formula.

Enter Coordinates

A Departure

Latitude (°)

Longitude (°)

South/West = negative. Decimal degrees only.

B Destination

Latitude (°)

Longitude (°)

Quick examples:

Enter coordinates and click Calculate

Decimal degrees · South/West are negative

Copied!

Summary

Enter two sets of latitude/longitude coordinates to get the great-circle distance and initial bearing using the Haversine formula.

How it works

Enter the departure latitude and longitude in decimal degrees (negative for South/West).
Enter the destination latitude and longitude in decimal degrees.
Click Calculate to run the Haversine formula instantly in your browser.
The tool returns the great-circle distance in nautical miles, kilometers, and statute miles.
Initial bearing (true course) from departure to destination is displayed in degrees.
Final bearing (true course) on arrival at the destination is also shown.

Use cases

Estimate the shortest flight distance for long-haul route planning.
Verify flight planning software outputs against a quick manual check.
Calculate initial bearing for navigation exercises and checkride preparation.
Compare great-circle vs. rhumb-line distances to understand fuel implications.
Determine the midpoint of a route for en-route alternate planning.
Use as a teaching aid for explaining spherical trigonometry in aviation ground school.
Quickly check distances between airports using their published lat/lon coordinates.
Plan ocean crossings where the curvature of the Earth significantly affects the route.

Frequently Asked Questions

Last updated: 2026-07-22 · Reviewed by Nham Vu