๐ Great-Circle Distance Calculator
Point A
Point B
Enter the latitude and longitude of two points to calculate the great-circle distance between them using the haversine formula, which treats the Earth as a sphere. This gives the shortest straight-line distance over the Earthโs surface, in both kilometers and miles.
How to use
- Enter the latitude and longitude of point A.
- Enter the latitude and longitude of point B.
- The great-circle distance is calculated automatically in kilometers and miles.
How the calculation works
This tool calculates the shortest distance along the Earth's surface (the great-circle distance) between two points from their latitude and longitude, using the haversine formula: a = sinยฒ(ฮlat รท 2) + cos(latโ) ร cos(latโ) ร sinยฒ(ฮlon รท 2) Distance = 2 ร Earth's radius ร atan2(โa, โ(1 โ a)) It uses the mean Earth radius of 6,371 km. Treating the Earth as a perfect sphere gives up to about 0.5% difference from the true ellipsoid. Latitude ranges from โ90 to 90 and longitude from โ180 to 180.
Worked example
Tokyo Station (35.681236, 139.767125) to Osaka Station (34.702485, 135.495951) โ about 403 km Tokyo Station to London (51.5074, โ0.1278) โ about 9,562 km Actual travel distances are longer because roads, railways and flight paths do not follow a perfect great circle.
Things to be aware of
- Map apps usually show a point's latitude and longitude when you right-click or long-press it.
- Enter southern latitudes and western longitudes as negative numbers (0.1278ยฐ W โ โ0.1278).
- Long-haul flight routes approximate great circles, which is why they look curved on a Mercator map.
FAQ
What formula does this use?
It uses the haversine formula, a standard method for computing great-circle distance between two points given their latitude and longitude, assuming Earth is a sphere with a radius of 6371 km.
Is this the same as driving distance?
No, this is the shortest straight-line distance over the Earthโs surface, not an actual road or flight route distance.
What format should I use for coordinates?
Use decimal degrees. Southern latitudes and western longitudes should be entered as negative numbers.