ICAO Methodology v13.1

    Flight Carbon Calculator

    Calculate CO₂ emissions for any flight — by cabin class, with RFI and offset pricing.

    1pax

    Enter a route above to calculate CO₂ emissions.

    Methodology

    Flight CO₂ emissions: what the numbers mean

    2.5%

    Global CO₂ share

    Aviation accounts for roughly 2.5% of global CO₂ emissions and up to 3.5% of total climate forcing when non-CO₂ effects are included via the RFI factor.

    600–900 kg

    Transatlantic economy

    A Frankfurt–New York economy flight emits approximately 600–900 kg CO₂ per passenger — equivalent to driving a petrol car 3,000–4,000 km.

    3–4×

    Business vs economy

    Business class passengers emit 3–4× more CO₂ than economy on the same flight, because emissions are allocated proportionally to seat floor area.

    How it works

    How the ICAO Carbon Emissions Calculator works

    The international standard for aviation carbon accounting, used by airlines, the EU ETS, and corporate travel tools worldwide.

    Full methodology explanation

    Three inputs

    The calculator uses great-circle distance between airports, the aircraft type (or fleet average), and the passenger load factor. Fuel burn per seat-km is derived from aircraft performance databases.

    CO₂ conversion

    Total fuel burn is multiplied by 3.16 to convert kerosene weight to CO₂ mass, then distributed across passengers weighted by seat class floor area.

    RFI factor (1.9×)

    An optional Radiative Forcing Index of 1.9× accounts for non-CO₂ climate effects at altitude — contrails, ozone, NOₓ. The GHG Protocol recommends CO₂-only for corporate reporting.

    Confidence scoring

    Each result includes a confidence score based on data completeness. Known aircraft types achieve high confidence; unknown aircraft use fleet-average values for the distance band.

    Reference data

    Common routes and their CO₂ emissions

    Economy class, per passenger, ICAO v13.1 methodology with fleet-average aircraft.

    Frankfurt (FRA) → New York (JFK)~527 kg CO₂London (LHR) → New York (JFK)~499 kg CO₂Paris (CDG) → New York (JFK)~525 kg CO₂Amsterdam (AMS) → New York (JFK)~528 kg CO₂Munich (MUC) → New York (JFK)~548 kg CO₂Vienna (VIE) → New York (JFK)~564 kg CO₂

    Click any route for a detailed CO₂ breakdown and live calculator.

    FAQ

    Flight Carbon Calculator — Frequently Asked Questions

    Everything you need to know about flight emissions and this calculator.