Antipode Finder

Overview

The Antipode Finder calculates the point on Earth's surface that lies diametrically opposite any latitude and longitude you supply. Drop in your home coordinates, a city centre, a hiking trailhead, or the lat/lng of a property listing, and the tool returns the exact antipodal coordinates along with a quick sanity check that the new point sits inside the valid WGS84 range.

Antipodes are useful for trivia, geocaching puzzles, classroom geography lessons, and route-planning thought experiments ("if I dug straight through the planet, where would I come out?"). Most populated land sits opposite open ocean, so the tool also makes it obvious why the "dig to China" myth almost never works out for anyone starting in the contiguous United States.

How it works

The antipode of a point is found by negating the latitude and shifting the longitude by 180 degrees. Formally, if your input is (lat, lng) in decimal degrees on the WGS84 ellipsoid, the antipode is (-lat, lng ± 180). The tool normalises the longitude back into the standard [-180, 180] range so the result is friendly to mapping libraries that reject 200 or -190.

No projection or datum conversion is needed because antipodes are a property of the sphere itself; the WGS84 ellipsoid is close enough to a sphere that the same formula works for everyday purposes. Polar inputs return the opposite pole regardless of the input longitude.

Examples

• New York City (40.7128, -74.0060) maps to roughly (-40.7128, 105.9940), deep in the southern Indian Ocean southwest of Australia.
• Wellington, New Zealand (-41.2865, 174.7762) maps to (41.2865, -5.2238), just off the Atlantic coast of Spain near Madrid - one of the rare city-to-near-city antipode pairs.
• The North Pole (90, 0) maps to (-90, 180), the South Pole.
• Greenwich Observatory (51.4769, 0.0) maps to (-51.4769, 180.0), an empty patch of the South Pacific.

FAQ

Why is my antipode almost always in the ocean?
About 71 percent of Earth's surface is water, and the land hemisphere is heavily biased toward the north. Only around 4 percent of land is antipodal to other land, so ocean answers are the norm.

Does this account for Earth's ellipsoidal shape?
For antipode lookups the sphere approximation is exact in terms of coordinates - the formula only flips latitude and longitude. Surface elevation, gravity and distance through the planet would need an ellipsoidal model, but those are not part of the lookup.

What range should my input use?
Latitude must sit between -90 and 90 and longitude between -180 and 180. The tool clamps and normalises out-of-range entries where it can.

Can I find the antipode of an address?
You will need to convert the address to coordinates first using a geocoder, then paste the lat/lng here.

Try Antipode Finder