What is a great circle?

A great circle is the largest circle that can be drawn on a sphere, formed by the intersection of the sphere with a plane passing through its center. The shortest path between two points on a sphere always lies along a great circle arc.

Why does the flight path on a map look curved?

Most maps use Mercator projection which distorts distances at high latitudes. Great circle routes appear curved on these maps but are actually the shortest paths on the globe.

What is the difference between initial and final bearing?

The initial bearing is the compass direction you head at the start of the journey. Because of Earth's curvature, you continuously change direction, so the final bearing is the compass heading when you arrive at your destination.

How accurate is this calculator?

The Haversine formula assumes a perfectly spherical Earth with radius 6371 km. Real Earth is slightly flattened at the poles (an oblate spheroid), so results may differ from geodetic calculations by up to 0.5% for very long distances.

What decimal degree format should I use?

Enter positive values for North latitude and East longitude, negative values for South latitude and West longitude. For example, New York is approximately 40.7128° N, −74.0060° W, entered as 40.7128 and −74.0060.

Great Circle Distance Calculator

Calculate the shortest distance between two points on Earth using the Haversine formula, with bearing and estimated flight time.

Coordinates Input

Quick Select — Famous Routes

A Point A

Latitude (°N positive)

Longitude (°E positive)

B Point B

Latitude (°N positive)

Longitude (°E positive)

Enter coordinates or select a famous route, then click Calculate Distance.

Summary

Calculate the shortest distance between two points on Earth using the Haversine formula, with bearing and estimated flight time.

How it works

Enter the latitude and longitude (decimal degrees) for Point A.
Enter the latitude and longitude for Point B.
The tool applies the Haversine formula on a sphere of radius 6371 km to get the arc distance.
Initial and final bearings are derived from the coordinate geometry using atan2.
Distance is shown in kilometers and miles, with an estimated flight time at 900 km/h.

Use cases

Plan international flight routes and estimate travel times.
Calculate sailing distances between ports for navigation.
Determine the shortest radio or satellite link path between two stations.
Verify map distances in geographic information system (GIS) work.
Estimate fuel requirements for long-haul aviation routes.

Frequently Asked Questions

Last updated: 2026-09-19 · Reviewed by Nham Vu