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Input format: 34.456 - 34.456 N - 34º25'14.340"N
LatitudeLongitude
Point r_1 * *
Point r_2 * *
Distance
d (r1 -> r2)		Heading
α

nm (1 nm ≡ 1852 m)

km

º
d (r1 -> r2)α1 α2

nm (1 nm ≡ 1852 m)

km

º (initial)

º (final)

This calculator determines the distance, d (r1,r2), between two positions on the earth's surface, r1 and r2, using two methods:

  1. the "plain sailing" method, which connects the two points by a straight line. It is also known as the Haversine method with an accuracy of about 0.3%.

    (This method should not be used for long distances because the strait line will go through the earth's interior.)

  2. using an ellipsoid model for the earth geoid. In this case the computation is done using the Thaddeus Vincenty's algorithm (Direct and Inverse Solutions of Geodesics on the Ellipsoid with application of nested equations, 1975). In this algorithm, the ellipsoid is given by the WGS-84 datum that provides distances with accuracies of 0.5 mm and 0.000015″ in the heading (Note)

In both cases, the convention is that north latitudes and west longitudes are positive, south latitudes and east longitudes are negative.

Note: For a detailed information about the computation and the JavaScript implementation look at the Chris Veness's webpage.