What is the difference between Haversine and Vincenty?

Haversine assumes the Earth is a perfect sphere and computes the great-circle distance. It is fast and accurate to within 0.5% for most purposes. Vincenty uses the WGS84 ellipsoid (the actual shape of Earth, slightly flattened at the poles) and is accurate to within 0.5 mm. For everyday use the difference is negligible; for surveying, aviation, or long-distance navigation, use Vincenty.

What is the midpoint?

The midpoint is the geographic centre of the great-circle arc between two coordinates — the point that is equidistant from both along the shortest path on the Earth's surface. It is not the simple average of the latitudes and longitudes, which would give a slightly different result for longer distances.

GIS · Navigation

Coordinate Distance Calculator

Q: What coordinate formats does this tool accept?

The tool accepts three formats: (1) Decimal Degrees (DD) — e.g. 51.5074 or -0.1278; (2) Degrees Minutes Seconds (DMS) — e.g. 51°30'26"N or 51 30 26 N; (3) Degrees Decimal Minutes (DDM) — e.g. 51°30.4333'N. All three can be mixed — you can enter Point A in DD and Point B in DMS.

Q: What is bearing?

Bearing is the direction of travel from one point to another, measured in degrees clockwise from true north (0° = north, 90° = east, 180° = south, 270° = west). The initial bearing is the direction you start heading when leaving Point A. The final bearing is the direction you arrive at Point B from. For long distances on a curved Earth these differ because you follow a great-circle arc, not a straight compass heading.

Q: What are nautical miles?

A nautical mile is defined as exactly 1,852 metres (1.852 km). It is used in maritime and aviation navigation because 1 nautical mile equals 1 arcminute of latitude — making chart reading and dead reckoning straightforward. 1 knot = 1 nautical mile per hour.

Calculate the distance between two GPS coordinates. Get km, miles, nautical miles, bearing, and midpoint — using Haversine or Vincenty formula.

What This Tool Calculates

Great-circle distance — the shortest path between two points on the Earth's surface.

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6 distance units

Results in km, miles, nautical miles, metres, feet, and yards — all computed from the same geodetic calculation.

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Bearing

Initial bearing (direction you leave A heading to B) and final bearing (direction you arrive at B), both with 16-point compass direction (N, NNE, NE…).

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Midpoint

The geographic centre of the great-circle arc between A and B — not a simple average but the true spherical midpoint.

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Vincenty formula

Uses the WGS84 ellipsoid model for sub-millimetre accuracy. Haversine (spherical model) is also available. For most purposes both give virtually identical results.

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Multi-point route

Switch to Route mode to add up to any number of waypoints. See each leg distance and the total route distance.

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Any coordinate format

Accepts decimal degrees (51.5074), DMS (51°30'26"N), DDM (51°30.4333'N), and decimal with direction (51.5074N). Formats can be mixed between the two points.

How to Use

Enter coordinates

Type or paste latitude and longitude for both points. Accepts decimal degrees, DMS, or DDM. You can optionally name each point. Click "Sample" to see an example (London → Paris).

Choose formula

Vincenty uses the WGS84 ellipsoid and is more accurate for long distances. Haversine treats Earth as a sphere — simpler but within 0.5% of Vincenty for most practical distances.

Read the results

Distance appears in km, miles, nautical miles, metres, feet, and yards. Initial and final bearing show the direction of travel. Midpoint gives the geographic centre of the route.

Use Route mode

Switch to "Route" mode for multi-point trips. Add as many waypoints as you need — each leg distance and the total are calculated automatically as you type.

Frequently Asked Questions

Haversine assumes the Earth is a perfect sphere (radius 6371 km) and computes the great-circle distance. It is fast and accurate to within 0.5% for most purposes. Vincenty uses the WGS84 ellipsoid (semi-major axis 6378.137 km, flattening 1/298.257) which better represents Earth's actual shape — slightly flattened at the poles. Vincenty is accurate to within 0.5 mm. For everyday use the difference is negligible. For surveying, aviation, or precise long-distance navigation, use Vincenty.

Three formats are supported: (1) Decimal Degrees (DD) — e.g. 51.5074 or -0.1278; (2) Degrees Minutes Seconds (DMS) — e.g. 51°30'26"N or 51 30 26 N; (3) Degrees Decimal Minutes (DDM) — e.g. 51°30.4333'N. You can also write 51.5074N or 0.1278W. Formats can be mixed between the two points.

Bearing is the direction of travel measured in degrees clockwise from true north (0° = north, 90° = east). The initial bearing is the direction you start heading when leaving Point A. The final bearing is the direction you are travelling when you arrive at Point B. These differ for any non-trivial distance because you follow a great-circle arc on a curved Earth — your heading changes continuously along the route.

A nautical mile is exactly 1,852 metres (1.852 km). It is the standard unit in maritime and aviation navigation because 1 nautical mile equals 1 arcminute of latitude — making chart reading and dead reckoning intuitive. Speed in nautical miles per hour is called a knot. 1 nm = 1.15078 statute miles.

On a Mercator map (used by most web maps) straight lines are lines of constant bearing (rhumb lines), not the shortest path. The shortest path between two points on a sphere curves toward the nearest pole — that is the great-circle route. For a flight from London to Los Angeles, the great-circle route passes over Greenland, which looks like a detour on a flat map but is actually shorter. The great-circle distance is always ≤ the rhumb-line distance.

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