Calculator tool
How this calculator works
Use the explanation to understand the formula, assumptions, and practical limits behind the calculator result.
What Distance Is Being Measured
This calculator measures the shortest path over Earth's surface between two latitude/longitude points. That path is called a great-circle distance. It is the curved-surface version of a straight line.
Why the Earth Matters
On a flat map, two cities may look farther apart or closer together than they really are because maps stretch a round Earth onto a flat page. The calculator uses a globe-aware formula so the result follows Earth's curvature instead of treating the planet as a flat sheet.
A Useful Distinction
Great-circle distance is not the same as driving distance. Roads bend around mountains, rivers, buildings, and borders, so a route by car is usually longer than the direct surface distance.
When It Is Good Enough
This estimate is useful for geography, aviation-style comparisons, and checking point-to-point separation. For walking, driving, or delivery planning, use a route service that knows the actual roads.
Frequently asked questions
What is the difference between straight-line distance and driving distance?
Straight-line distance measures the shortest path between the two coordinates. Driving distance follows real roads, so it is usually longer because routes must bend around obstacles and use available streets.
How accurate is GPS distance measurement?
The formula can be precise, but the final result is only as accurate as the coordinates you enter. Rounded or noisy GPS coordinates can shift the answer.
Why does flying from Los Angeles to London over the Arctic seem shorter than flying directly east?
Because the Earth is round. The shortest route on a globe can look curved when it is drawn on a flat map.
How do I convert degrees of latitude and longitude to kilometers?
Latitude lines stay roughly the same distance apart, but longitude lines get closer together near the poles. That is one reason coordinate differences cannot always be treated like equal grid squares.
