How the distance is calculated
The tool measures the shortest path over the Earth’s surface — the geodesic — on the WGS 84 ellipsoid using Vincenty’s formula, accurate to a millimetre. Many calculators use the simpler haversine formula on a sphere, which can be off by up to 0.5%. Both values are shown so you can compare.
Bearings
The initial bearing is the compass direction you set off in from point A, measured clockwise from true north. On a long route the direction changes along the way, so the final bearing — the direction you arrive at point B — is different. On a flat map the geodesic appears as a curve; that curve is the straight line on the globe.
Using the tool
- Paste coordinates for A and B in any format, search a place, or click the map — the first click sets A, the next sets B.
- Drag either marker to adjust it.
- The midpoint is the point halfway along the geodesic, handy for choosing where to meet.
Straight line, not road distance
This is the distance “as the crow flies”. Driving or walking distance follows roads and is always longer.
Frequently asked questions
How do I calculate the distance between two coordinates?
Enter or click two points. The tool computes the geodesic distance on the WGS 84 ellipsoid and shows it in kilometres, miles and nautical miles.
What is the difference between haversine and Vincenty?
Haversine assumes a perfect sphere and can be off by up to about 0.5%. Vincenty uses the ellipsoid and is accurate to around a millimetre.
What is the initial bearing?
The compass direction from point A toward point B at the start of the route, measured clockwise from true north.