How the Antipode Calculator Works
Every point on Earth has exactly one antipode: the point diametrically opposite it, as if you drilled a straight line through the planet's center and kept going until you popped out the other side. This calculator finds that point from any latitude and longitude, along with how far apart the two points are.
The formula
Given a latitude lat and longitude lon in decimal degrees:
- Antipode latitude = −lat (flip the hemisphere — north becomes south, south becomes north, the same number of degrees from the equator).
- Antipode longitude = lon + 180° if lon ≤ 0°, or lon − 180° if lon > 0° (shift halfway around the globe, then normalize back into the −180° to 180° range).
Because the antipode always sits at the opposite end of a line through the planet's center, the distance between any point and its antipode is fixed by Earth's size alone — it never depends on where the point is. Using a mean Earth radius of 6,371 km, two distances follow directly:
- Surface (great-circle) distance = π × R ≈ 20,015 km (12,437 mi) — the shortest path along the globe's curved surface, exactly half of Earth's circumference.
- Through-Earth distance = 2 × R ≈ 12,742 km (7,918 mi) — the straight-line "dig a hole" distance, equal to Earth's diameter.
Worked example
New York City sits at about 40.7128° N, 74.0060° W. Flipping the latitude gives 40.7128° S; shifting the longitude by 180° gives 105.9940° E. That antipodal point falls in the Indian Ocean, southwest of Australia — a reminder that most land-based antipodes end up in open water, since oceans cover roughly 71% of Earth's surface.
Reading the result
The two coordinate results show where the antipode is; the two distance results are constants that apply to every calculation, since any point and its antipode are always separated by the same share of Earth's circumference and diameter. To use the antipode for mapping or navigation, plug the resulting latitude and longitude directly into a map search.