Flight CO2 emissions estimator API

Estimate flight CO2e from distance (or origin/dest lat-lon via the haversine great-circle formula) using DEFRA per-passenger-km haul factors (short 0.158, medium 0.13, long 0.114 kg/km), a cabin multiplier (economy 1, premium 1.6, business 2.9, first 4) and the IPCC 1.9x radiative-forcing multiplier for non-CO2 high-altitude effects. Returns per-passenger and total kg/tonnes CO2e plus tree equivalents. Answers 'CO2 of a 5000km flight','business class footprint','round-trip emissions for 2 passengers','flight emissions JFK to LHR'.

Price$0.01per request

MethodPOST

Route/v1/calc/carbon-flight-emissions

StatusLive

MIME typeapplication/json

Rate limit120/minute

CacheNo cache

carbonflightaviationemissionsco2travelfootprintsustainability

API URLhttps://x402.hexl.dev/v1/calc/carbon-flight-emissions

Integration docs

Example request

{
  "distanceKm": 5000,
  "cabin": "economy"
}

Example response

{
  "distanceKm": 5000,
  "haul": "long",
  "cabin": "economy",
  "passengers": 1,
  "roundTrip": false,
  "emissionFactorKgPerKm": 0.114,
  "cabinMultiplier": 1,
  "radiativeForcingMultiplier": 1.9,
  "perPassengerKgCO2e": 1083,
  "totalKgCO2e": 1083,
  "totalTonnesCO2e": 1.083,
  "equivalentTrees": 51.57
}

Input schema

{
  "type": "object",
  "required": [],
  "properties": {
    "distanceKm": {
      "type": "number",
      "description": "one-way great-circle distance in km",
      "examples": [
        5000
      ]
    },
    "originLat": {
      "type": "number"
    },
    "originLon": {
      "type": "number"
    },
    "destLat": {
      "type": "number"
    },
    "destLon": {
      "type": "number"
    },
    "cabin": {
      "type": "string",
      "enum": [
        "economy",
        "premium",
        "business",
        "first"
      ],
      "default": "economy"
    },
    "passengers": {
      "type": "number",
      "default": 1
    },
    "roundTrip": {
      "type": "boolean",
      "default": false
    },
    "radiativeForcing": {
      "type": "boolean",
      "default": true
    }
  }
}

Output schema

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