As travelers, corporate travel managers, and travel agents are increasingly demanding precise flight CO2 emission information, an accurate and standardized calculation methodology is critical. 

This is why IATA developed a Recommended Practice Per-Passenger CO2 Calculation Methodology. The methodology considers everything from airline fuel measurement protocols, passengers vs. cargo CO2 allocation, cabin class factors and much more. Used in combination with verified airline operational data, the methodology provides the most accurate calculation results and transparency to everyone interested in understanding the carbon footprint from flying activity.

Aviation is committed to achieving net zero CO2 emissions by 2050. By creating an accepted industry standard for calculating aviation’s carbon emissions, the industry is providing transparency on the calculation of  passenger environmental impact when flying. 

IATA and its member airlines have worked together to develop an accurate and transparent methodology using verified airline operational data. This provides the most accurate CO2 calculation for organizations and individuals to make informed choices based on estimated carbon emissions for their flights. This includes decisions on investing in voluntary carbon offsetting or sustainable aviation fuel (SAF) use.

The standard has been developed for use by the following parties:

  • Airlines
  • Online Flight Search Engines
  • Online Travel Agents and Travel booking Systems
  • Corporate Travel Management Companies
  • Passenger & Corporate Offset Solutions
  • Airline Voluntary Passenger Offset Programs


To download the free standard Passenger CO2 Calculation Methodology, please complete this form and you will receive an email with further instructions. 

IATA Recommended Practice Per-Passenger CO2 Calculation Methodology

IATA’s Recommended Practice Per-Passenger CO2 Calculation Methodology was developed together with an airline working group consisting of 20 major airlines. Major aircraft manufacturers validated the Methodology as it was being developed. In parallel, IATA consulted and discussed with various stakeholders across the industry, including international standards-setting bodies; and major freight forwarders and shippers.

IATA’s Methodology takes into account the following factors:

  • Guidance on fuel measurement, aligned with the Carbon Offsetting and Reduction Scheme for International Aviation (CORSIA)
  • Clearly defined scope to calculate CO2 emissions in relation to airlines’ flying activities
  • Guidance on non-CO2 related emissions and Radiative Forcing Index (RFI)
  • Weight-based calculation principle: allocation of CO2 emission by passenger and belly cargo
  • Guidance on passenger weight, using actual and standard weight
  • Emissions Factor for conversion of jet fuel consumption to CO2, fully aligned with CORSIA
  • Cabin class weighting and multipliers to reflect different cabin configurations of airlines
  • Guidance on Sustainable Aviation Fuel (SAF) and carbon offsets as part of the CO2 calculation

The RP confines its calculation scope strictly to the fuel burn and CO2 emissions related to flight operations. However, the RP gives flexibility to include upstream CO2 emissions (i.e. emissions that are in relation to the production or transportation of jet fuel, as opposed to direct emissions, resulting from combustion during a flight), should this be required by local regulations and can be optionally added.

In such case, it is important to follow the local guidelines for inclusion of upstream emissions. As part of the display of per-passenger emissions, it must be clearly indicated that upstream emissions were included in the calculation, specifying the factor used.

In addition, the RP provides a certain level of flexibility for airlines or other users of the RP Methodology when it comes to non-CO2 and non-aircraft emissions, or Radiative Forcing Index (RFI). While the RP does not recommend taking them into account, the user can display non-CO2 and non-aircraft emissions, and RFI, indicating that they were included in the calculation.

Some elements align and other important elements have been reviewed, updated and improved to reflect recent developments in the industry. For example, the allocation of fuel in relation to operational equipment weight and cabin class has been revised based on airline and aircraft manufacturer information, while guidance on SAF and carbon offsets has been included.

IATA’s Recommended Practice Per-Passenger CO2 Calculation Methodology is a methodology that can only be used to calculate passenger CO2 emissions and can be useful as part of an airline or industry voluntary offset program. A carbon credit scheme, such as CORSIA tracks overall emissions by airline on international routes, whereas the CO2 calculation methodology offers guidance to calculate emissions on a per passenger basis. These are two different types of calculations.

IATA’s Methodology provides per pax CO2 emissions calculation guidance and should not be mixed up with carbon offsetting schemes, unless as part of an airline or industry voluntary passenger offset program.