Vincenty ellipsoidal distance API

Computes the geodesic distance between two coordinates on the WGS-84 ellipsoid via Vincenty's iterative inverse formula (sub-meter accurate, ~0.3-0.5% better than haversine), plus initial/final bearings and the spherical correction. Answers 'What is the precise ellipsoidal distance between two points?', 'How far off is haversine from the true geodesic?'.

Price$0.06per request

MethodPOST

Route/v1/geo/vincenty-distance

StatusLive

MIME typeapplication/json

Rate limit120/minute

Cache0s public

geogisvincentygeodesicdistanceellipsoidalwgs84haversinegreat-circle

API URLhttps://x402.hexl.dev/v1/geo/vincenty-distance

Integration docs

Example request

{
  "from": {
    "latitude": 51.5074,
    "longitude": -0.1278
  },
  "to": {
    "latitude": 48.8566,
    "longitude": 2.3522
  }
}

Example response

{
  "from": {
    "latitude": 51.5074,
    "longitude": -0.1278
  },
  "to": {
    "latitude": 48.8566,
    "longitude": 2.3522
  },
  "ellipsoid": "WGS-84",
  "distanceMeters": 343923.12,
  "distanceKm": 343.92312,
  "distanceMiles": 213.703853,
  "distanceNauticalMiles": 185.703629,
  "initialBearing": 148.045928,
  "finalBearing": 149.951405,
  "iterations": 3,
  "haversineKm": 343.556535,
  "ellipsoidalCorrectionKm": 0.366585,
  "interpretation": "Vincenty geodesic distance 343.923 km (vs 343.557 km spherical); the ellipsoidal model is sub-meter accurate where haversine errs ~0.3-0.5%."
}

Input schema

{
  "type": "object",
  "required": [
    "from",
    "to"
  ],
  "properties": {
    "from": {
      "type": "object",
      "required": [
        "latitude",
        "longitude"
      ],
      "properties": {
        "latitude": {
          "type": "number"
        },
        "longitude": {
          "type": "number"
        }
      },
      "examples": [
        {
          "latitude": 51.5074,
          "longitude": -0.1278
        }
      ]
    },
    "to": {
      "type": "object",
      "required": [
        "latitude",
        "longitude"
      ],
      "properties": {
        "latitude": {
          "type": "number"
        },
        "longitude": {
          "type": "number"
        }
      },
      "examples": [
        {
          "latitude": 48.8566,
          "longitude": 2.3522
        }
      ]
    }
  }
}

Output schema

{
  "type": "object",
  "additionalProperties": true
}