Antipode coordinates calculator
The antipode of New York (40.7128° N, 74.006° W) is 40.7128° S, 105.994° E: the latitude flips sign and the longitude moves 180°. Enter any point in decimal degrees and get its exact opposite on a spherical Earth, with its hemisphere. Free in your browser.
- Free
- Runs in your browser
- No sign-up
- Your data stays on your device
Run — free
Worked example
- Latitude
- 40.7128
- Longitude
- -74.006
- Antipode latitude
- -40.7128
- Antipode longitude
- 105.994
- Angular separation deg
- 180
- Hemisphere
- southern
The antipode of a place on Earth is the single point diametrically opposite it: the location you would reach if you drilled a straight tunnel through the planet’s center and came out the other side. On a sphere the construction is elementary and exact. Negate the latitude so the Northern Hemisphere becomes Southern and vice versa, then add one hundred eighty degrees to the longitude and wrap the result into the conventional interval from negative one hundred eighty to positive one hundred eighty. Every pair of antipodal points is separated by one hundred eighty degrees of great-circle arc—half the circumference—and the two points share no unique longitude when either sits on a pole because all meridians meet there. This calculator accepts decimal-degree latitude and longitude, validates both against geographic ranges, and returns the antipodal coordinates as nested and flat fields, a fixed angular separation of one hundred eighty degrees, a hemisphere label for the antipode, and the closed-form formula string used. Place-name geocoding and ellipsoid refinements are out of scope: you supply numbers, you get the classical spherical opposite.
How the spherical antipode formula works
Start with a geographic point written as latitude phi and longitude lambda in decimal degrees, with north and east positive. Geographic latitude is only valid on the closed interval from negative ninety to positive ninety; longitude is only valid on the closed interval from negative one hundred eighty to positive one hundred eighty. The antipodal longitude is the input longitude plus one hundred eighty degrees, then normalized into the open-closed interval that prefers positive one hundred eighty over negative one hundred eighty at the antimeridian.
That normalization is the same wrap used by sibling great-circle tools in this catalog, so pipelines that chain destination, rhumb, and antipode steps stay consistent. By construction the great-circle angular separation between a point and its antipode is always one hundred eighty degrees—exactly half a revolution—independent of where you start. There is no network call, no random seed, no wall-clock timestamp, and no model drift; identical inputs always produce identical outputs.
If you need an ellipsoid-aware antipode on WGS84, treat that as a different search intent and a different landing rather than overloading this classical spherical tool.
What you send and what you get back
Send two finite numbers under the fields latitude and longitude representing the input point in decimal degrees. Both fields are required. Examples that work out of the box include New York City near forty point seven one two eight north and seventy-four point zero zero six west, Madrid near forty point four one six eight north and three point seven zero three eight west, and the Greenwich reference near fifty-one point four seven seven eight north and zero degrees.
Classic sanity checks include the origin zero zero mapping to zero latitude and one hundred eighty longitude, a pure southern point mapping to a pure northern point with longitude shifted by one hundred eighty, and pole inputs mapping to the opposite pole.
Where antipode calculators show up in real work
Geography teachers assign antipode drills so students connect hemisphere flips with longitude wrapping and the idea that most landmasses face ocean on the opposite side of the globe. Travel writers and podcast producers look up “what is on the other side of the world from here” when packaging destination features, and a deterministic coordinate tool avoids hand-wavy maps that place the antipode hundreds of kilometers off.
Game designers and procedural world builders place opposite poles, twin dungeons, or portal exits by reflecting a spawn coordinate through the planet center without inventing ad-hoc sign rules. Emergency-planning and educational visualizations that paint day and night hemispheres sometimes highlight the antipode of a solar sub-point as a teaching overlay. If you later need great-circle destinations from bearing and distance, rhumb-line destinations, decimal-to-DMS conversion, or map-tile indices from lat and lon, treat those as separate search intents and landings rather than overloading this antipode coordinates calculator page.
What you can do with it
Classroom antipode drills
Generate opposite-side lat/lon pairs for homework and auto-graders so hemisphere flips and ±180° longitude wrap always match one ground truth.
Travel and trivia content
Look up the classical opposite point of a city coordinate for articles, maps, and “other side of the world” features without geocoding or guesswork.
Game worlds and portal exits
Reflect spawn coordinates through the planet center for twin locations, poles, or portal destinations with a stable spherical formula.
FAQ
How is the antipode calculated?
On a sphere the antipodal latitude is the negation of the input latitude, and the antipodal longitude is the input longitude plus 180°, normalized into (−180, 180]. The great-circle separation is always 180°.
What latitude and longitude ranges are accepted?
Latitude must be a finite number in [−90, 90]. Longitude must be a finite number in [−180, 180].
Does this use an ellipsoid such as WGS84?
No. This tool uses the classical spherical antipode. Ellipsoid-aware antipodes need iterative geodesic math and are a different product intent.
What happens at the poles?
The North Pole maps to the South Pole and vice versa. Longitude is still shifted by 180° and normalized; at a pole all longitudes meet, so the reported meridian is conventional.
What does it cost?
The browser tool is free and runs locally.
Related tools
For developers — API access
Everything on this page is available programmatically. This section is for teams who want to wire it into their own systems; everyone else can just use the tool above.
API endpoint
Prefer to automate it? One authenticated POST creates the task; the result comes back by webhook or a signed link. The same capability also runs here on the web, by email and from Telegram — and soon from our app too.
Call it from your stack
curl -X POST https://api.kit.forhosting.com/geo/antipode \
-H "Authorization: Bearer $KIT_KEY" \
-H "Content-Type: application/json" \
-d '{"latitude":40.7128,"longitude":-74.006}'const res = await fetch("https://api.kit.forhosting.com/geo/antipode", {
method: "POST",
headers: {
"Authorization": `Bearer ${process.env.KIT_KEY}`,
"Content-Type": "application/json"
},
body: JSON.stringify({
"latitude": 40.7128,
"longitude": -74.006
})
});
const { task_id } = await res.json();import os, requests
res = requests.post(
"https://api.kit.forhosting.com/geo/antipode",
headers={"Authorization": f"Bearer {os.environ['KIT_KEY']}"},
json={
"latitude": 40.7128,
"longitude": -74.006
},
)
task_id = res.json()["task_id"]<?php
$res = file_get_contents("https://api.kit.forhosting.com/geo/antipode", false, stream_context_create([
"http" => [
"method" => "POST",
"header" => "Authorization: Bearer " . getenv("KIT_KEY") . "\r\nContent-Type: application/json",
"content" => '{"latitude":40.7128,"longitude":-74.006}',
],
]));
$task = json_decode($res, true);body := bytes.NewBufferString(`{"latitude":40.7128,"longitude":-74.006}`)
req, _ := http.NewRequest("POST", "https://api.kit.forhosting.com/geo/antipode", body)
req.Header.Set("Authorization", "Bearer "+os.Getenv("KIT_KEY"))
req.Header.Set("Content-Type", "application/json")
res, _ := http.DefaultClient.Do(req)Example request
{
"latitude": 40.7128,
"longitude": -74.006
}Example response
{
"task_id": "tsk_a1b2c3d4e5f6a1b2c3d4e5f6",
"type": "geo.antipode",
"status": "queued",
"_links": {
"result": "/tasks/tsk_…/result"
}
}The API is asynchronous: the call returns a task_id immediately and the result arrives by webhook. Polling is capped at 1 req/s per task.
Pricing
Published price — no tokens, no invented credits. A failed task is never charged.
Errors
| HTTP | Code | Meaning |
|---|---|---|
401 | unauthorized | Missing or invalid API key. |
402 | insufficient_balance | Your balance doesn't cover the task price. |
404 | unknown_type | That task type doesn't exist. |
429 | rate_limited | Too many requests. Use the webhook instead of polling. |
Technical notes
How the spherical antipode formula works
The calculator rejects missing fields, non-numeric strings, NaN, Infinity, and any value outside those ranges with invalid_input so callers can correct the payload before retrying. On a sphere the antipodal latitude is simply the negation of the input latitude: a city at forty degrees north maps to forty degrees south, the North Pole maps to the South Pole, and an equatorial point stays on the equator with only longitude flipped.
What you send and what you get back
On success the response echoes the cleaned input coordinates, returns an antipode object with latitude and longitude plus the same two values as flat antipode_latitude and antipode_longitude fields for clients that prefer a shallow schema, sets angular_separation_deg to one hundred eighty, labels hemisphere as northern, southern, or equatorial according to the sign of the antipodal latitude, and includes method spherical_antipode with the short formula string. Missing latitude, missing longitude, latitude ninety-one, or longitude two hundred all fail with invalid_input and a message that names the problem so scripts can branch without scraping free text. Pricing for successful API calls is the published base of $0.002 per item; validation failures do not consume prepaid balance.
Where antipode calculators show up in real work
Because this capability is a pure parse engine, API pricing is the published base of $0.002 per successful item and failed validation does not consume balance.