Zero by Fifty
ICAO Methodology v13.1 · August 2024

We compute aviation CO₂ emissions the way regulators do.

Our REST API estimates per-passenger flight carbon emissions. We serve ground-truth values from an ICAO reference dataset where available, and fall back to a calibrated distance regression everywhere else — consistent with ICAO and IATA methodologies.

What we do

One POST and we return emissions, the offset in trees, and the cost to offset.

Reference-grade results

We run exact and reverse lookups against an ICAO emissions reference table for covered routes and cabin classes.

Graceful fallback

For routes outside the dataset we use a piecewise log-linear regression segmented by distance band and aircraft category (~15.5% MAPE).

Cabin-aware

We weight economy, premium economy, business, and first by ICAO Yseat factors (1.00 → 7.97).

Offset built in

Every result we return includes trees required and offset cost, using EPA's 21 kg CO₂/tree/year over a 40-year lifespan.

How we calculate it

We run every POST /calculate through this priority chain.

  1. Exact reference lookup — we query the ICAO reference table for (origin, destination, cabin_class). ~0% error.
  2. Reverse reference lookup — we swap origin and destination against the same table. ~0% error.
  3. Regression fallback — we compute CO₂ = exp(b) × distance_corrected_kma, segmented by distance band × aircraft category. ~15.5% MAPE.

Try our API

Our compute and history endpoints may require an X-API-Key header. Use the interactive Swagger UI to send authenticated requests.

Request

POST /api/v1/carbon-calculator/calculate
Content-Type: application/json
X-API-Key: <your-key>

{
  "origin": "JFK",
  "destination": "LHR",
  "cabin_class": "economy"
}

Response

201 Created

{
  "origin": "JFK",
  "destination": "LHR",
  "cabin_class": "economy",
  "distance_km": 5554.0,
  "co2_kg_per_passenger": 302.4,
  "trees_required": 1,
  "offset_amount": 10.0,
  "emissions_on_icao": { ... }
}

Key constants

The figures we use, from ICAO Methodology v13.1 and EPA offset data.

ConstantValue
CO₂ conversion factor3.16 kg CO₂ / kg fuel
Yseat — Economy / Premium / Business / First1.00 / 1.52 / 5.20 / 7.97
CO₂ absorbed per tree21 kg / year (EPA)
Tree lifespan · cost40 years · $10