How to Calculate Distance Between Two GPS Coordinates
To find the straight-line distance between two GPS points, enter both latitudes and longitudes into a Haversine distance calculator, which returns the great-circle distance in kilometres, miles, and nautical miles plus the initial bearing. This is the as-the-crow-flies distance across Earth's curved surface, not a road route, and it updates the instant both points are valid.
Measuring distance on a sphere is not the same as a ruler on a flat map. The shortest path between two coordinates follows a great circle, which is why flight paths curve toward the poles. A dedicated calculator applies the right formula so your numbers actually reflect reality.
Why great-circle distance matters
Pilots and sailors plan legs with it, runners and cyclists estimate straight-line distances, logistics teams sanity-check route lengths, and developers verify their own Haversine implementations against a trusted reference. The tool also reports the initial compass bearing from the first point to the second, both in degrees and as a 16-point compass direction, which is what you need to set an initial heading.
How to calculate distance in your browser
- Enter the latitude and longitude of the first point — decimal degrees or DMS such as 40°26'46"N both work.
- Enter the latitude and longitude of the second point in the same flexible way.
- Read the great-circle distance shown at once in kilometres, statute miles, and nautical miles.
- Note the initial bearing in degrees and its compass direction, then copy any value you need.
Haversine vs. Vincenty: which formula to trust
Two formulas dominate distance calculations, and knowing when each fits keeps your accuracy honest:
| Method | Earth model | Accuracy | Best for |
|---|---|---|---|
| Haversine | Perfect sphere | Within about 0.3% | Planning, aviation estimates, app development |
| Vincenty / Karney | WGS-84 ellipsoid | Down to millimetres | Surveying-grade precision work |
For the vast majority of practical checks, Haversine is the sensible choice: it is fast, closed-form, and accurate to roughly 3 km over a 1,000 km leg. Vincenty is more precise but slower and can fail to converge for nearly antipodal points, so it is reserved for work that genuinely needs sub-metre accuracy.
Key features and benefits
- Haversine great-circle distance in km, miles, and nautical miles.
- Initial bearing in degrees plus a 16-point compass direction.
- Accepts decimal degrees and DMS input like 51°28'40"N.
- Live results with no submit button to press.
- 100% client-side — coordinates are never uploaded.
- Free, unlimited, and works offline as a PWA.
Try the Distance Calculator now — it's free and runs entirely in your browser.
Frequently asked questions
How accurate is the Haversine formula?
It assumes a spherical Earth, so it is typically within 0.3% of the true distance — about 3 km over a 1,000 km leg. That is fine for planning and development. Surveying-grade work should use Vincenty or Karney on the WGS-84 ellipsoid instead.
What is an initial bearing?
It is the compass direction you would face at the start point to head toward the destination along the great circle. Because great circles curve relative to lines of longitude, the bearing shifts as you travel, so the initial bearing is only exact at the departure point.
Why do transatlantic flights pass over Greenland?
Because the shortest route between two points on a sphere is a great circle, which looks curved toward the pole on a flat map. New York to London naturally passes near Newfoundland and south of Greenland — the same path this calculator measures.
How long is a nautical mile versus a statute mile?
A nautical mile is 1,852 metres, defined as one minute of latitude, while a statute mile is 1,609.344 metres. That direct link to coordinates is why aviation and shipping use nautical miles, and this tool shows all three units together.
Can I measure driving distance with this?
No — this is straight-line great-circle distance, not a road route. It tells you how far apart two points are as the crow flies, which is ideal for planning and estimates but will read shorter than an actual drive that follows roads.
Related free tools
- Coordinate Converter — switch coordinates between DD, DMS, and DDM.
- Latitude Longitude Finder — validate and map raw coordinate text.
- KML Circle Generator — draw radius circles for Google Earth.
- Area Calculator — measure the area of a polygon.
Built by ByteVancer
ByteTools is a free product of ByteVancer, a software and web development studio that builds web apps, SaaS platforms, and custom software for businesses. If you need geospatial features or calculation-heavy tools built into your product, explore ByteVancer's services or get in touch.
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