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Access the air travel’s industry reliable and accurate CO2 emissions data

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IATA CO2 Connect is an emissions calculator developed with real airline data based on industry approved recommended practices that can easily be integrated into your operations.

Travel agencies, booking search engines, freight forwarders and corporate travel managers among others want to do their part in offering more accurate visibility on the carbon footprint of flights. Starting with providing your customers with accurate, transparent data is key to helping them track, reduce, report, and offset some of their carbon footprint.

 > Press release: IATA Secures More Data Contributors for CO2 Connect

 > Solutions blog: IATA CO2 Connect Adds Four Airlines as Data Contributors

Who is IATA CO2 Connect for?

CO2 Connect for Airlines



With increased demand and requirements to display CO2 emissions for flights, airlines need to consider how their CO2 information is calculated.

CO2 Connect for Travel Agencies

Travel Agencies and Booking Search Engines


Offer your customers the ability to compare the carbon footprint of flights and make informed decisions. Display CO2 emissions pre-flight for search or on the booking/confirmation. 

CO2 Connect - Corporate Travel

Corporate Travel


Assess the environmental impact of your companies flights and align future business travel with your company's sustainability goals.

Why choose IATA CO2 Connect?

Provide consistent and transparent CO2 calculations based on the IATA Recommended Practice 1726 using verified airline data. Use actual fuel burn data from 74 aircraft types, representing nearly 98% of active global passenger fleet. IATA CO2 Connect considers traffic data from 881 aircraft operators, representing approximately 93% of global air travel.

1. Get on the track of sustainability 

  • Get carbon emissions guidance directly from the air transport industry
  • Integrate sustainability into your strategy and for carbon reporting
  • Meet today's air passenger environmental expectations

2. Data accuracy

  • Use the industry's most accurate data provided directly from airlines
  • Data based on airline aircraft performance
  • Calculations based on industry approved recommended practices and methodology 

3. Easy to use

  • Simple API that can easily be integrated into your software or webpages
  • Effortlessly display carbon emissions to your customers
  • Compensation solution coming soon


Test our calculator

Simply search and select your departure and arrival airport. Choose the aircraft type and hit calculate. Not sure what the aircraft type is? The most common type on your route will be pre-selected. 

Note: This calculator uses a simplified version of CO2 Connect. 


Frequently Asked Questions


IATA CO2 Connect is an online tool providing the most accurate CO2 emission calculations for any given commercial passenger flight. It responds to the growing demand for CO2 data transparency linked to airline-specific and actual fuel burn and load factors. The tool is powered by the industry approved IATA Recommended Practice Per-Passenger CO2 Calculation Methodology which was conceived by more than 20 airlines and major aircraft manufacturers, in consultation with international standard-setting . This distinguishes IATA CO2 Connect from theoretical data models that already exist on the market today.

  1. Calculation of total CO2 emissions for a given flight.
  2. Distribution of CO2 between passenger and cargo payload based on weight.
  3. Allocation of CO2 between passengers considering expected occupancy and cabin classes.

IATA CO2 Connect utilizes the newly developed CO2 Calculation Methodology, adopted by IATA’s Passenger Service Conference in March 2022. This was conceived by more than 20 airlines and major aircraft manufacturers, in consultation with international standard-setting bodies and logistics services providers.

There are three main differentiation points between the IATA CO2 Connect calculator and other calculators:

  1. Actual airline data is used for aircraft type fuel burn and belly cargo weight. Applicable aircraft type values represent an average between different operators.

  2. For all routes found in a schedule database, a time-based approach is used as opposed to a distance-based one. The duration and the emissions of a flight can vary significantly depending on the direction of travel, and using a time-based approach captures these variations more accurately. For example, flights between North America and Europe tend to take longer on the westbound than on the eastbound and emissions estimates reflect this.

  3. The calculator is based on aircraft-specific fuel burn data, meaning it does not use an average of different aircraft types, nor does it apply static, distance-based factors.


Factors which influence the CO2 footprint of an individual’s air travel can generally be divided into two categories: factors which influence the emissions of a flight, and factors which influence the allocation of the aircraft’s emissions to individual passengers.

The key determinant of any given flight is fuel burn, driven by factors such as aircraft type or flight duration – the latter often influenced by weather and airspace efficiency. Generally, larger and heavier aircraft tend to emit more on a given route. However, their higher capacity may result in lower per-passenger emissions.

In order to accurately allocate the CO2 emissions per passenger, the weight ratio between passengers and cargo must be determined. The larger the share of cargo weight, the more emissions are allocated to it.

Once the share of the flight’s emissions attributed to all passengers is known, the allocation between individual passengers depends on:

  1. The total number of seats on the aircraft, as well as their distribution between different cabin classes; and
  2. How full the aircraft is, i.e., how many seats are occupied by passengers (passenger load factor).

A larger number of passengers onboard – whether through a larger number of seats or a larger portion of seats being filled – tends to result in lower CO2 emissions allocated to an individual passenger.

We are constantly building on the accuracy of the calculator which includes the aircraft type selection.  If you have noticed any issues, or have questions not answered in the FAQ below, please contact the IATA CO2 Connect team.  Please make sure to include all relevant information (and screen-shots, as applicable).

Calculation Methodology and Example

Passenger CO2 emissions are calculated in line with the IATA standard recommended practice RP1726. In practical terms, the calculations are performed in three key steps:

1. Calculating Total CO2 Emissions of a Flight:

A flight schedules database is queried based on the chosen route:

  • If a match is found, up to 10 aircraft types are available for user selection. By default, the most used aircraft type is pre-selected.
  • If no match is found, the (great circle) distance between the origin and destination airport is calculated based on the route. Up to 10 aircraft types that are flown on similar distances are available for user selection. By default, the most used aircraft type is pre-selected.

b. Total flight time (block time, from gate to gate) is based on the route and the chosen aircraft.

  • Scheduled flight times may vary on a specific route, even if they are operated by the same aircraft type. In these instances, a weighted average flight time is used.

c. The IATA CO2 Connect calculator is time-based. Hence, the flight time is multiplied with a fuel consumption factor (in kg/min) specific to the chosen aircraft type. This gives the total fuel consumption of a flight.

d. The fuel consumption is multiplied by the ICAO CORSIA CO2 emissions factor for jet kerosene of 3.16, resulting in the total CO2 emissions for the flight.

2. Allocating CO2 Emissions Between the Passengers and (Belly) Cargo: 

a. Projected number of passengers for a flight is calculated based on the cabin configuration of the selected aircraft type and the passenger load factor.

b. Total weight of all passengers (and their baggage) is calculated by multiplying the number of passengers by the standard weight of 100kg.

c. Projected (belly) cargo weight is determined based on the aircraft type.

d. A ratio of total passenger weight and total (passenger + belly cargo) weight is calculated.

e. The total CO2 emissions for the flight are multiplied by this ratio, resulting in the share of the flight’s emissions that is attributed to all the passengers.

  • The difference between the total CO2 emissions for the flight, and those that are attributed to all the passengers, are the CO2 emissions allocated to belly cargo.


3. Allocating CO2 Emissions to Individual Passengers Based on Cabin/Travel Class:

a. For each of the cabin classes (economy, premium economy, business, or first), the expected number of seats in the cabin class is determined, depending on the selected aircraft type.

b. CO2 emissions are allocated to passengers, depending on the cabin class, based on the CO2 emissions of all passengers and the ratio of [cabin class factor of chosen class] and the [sum for all classes of (number of seats in class * cabin class factor)]. For added clarity, please refer to the calculation example for economy class.

c. CO2 emissions are displayed for a passenger in the cabin class selected as the calculator input.


Yes, there is a calculation example. Please see below:


IATA CO2 Connect Calculator - calculation example

Please see the calculation steps in the following table with formulas, including actual numbers in brackets. Calculation steps refer to the previous question (“How are CO2 emissions calculated?”). The numbers used in the example are only for illustration purposes and do not reflect a real example. Should you try the exact same example with the IATA CO2 Connect calculator you will get the correct result.

The calculator derives time based on the route, as described in steps 1a-1b.

IATA CO2 Connect Calculator Calculation Formula

IATA CO2 Connect Calculator Formula Result



The following data is processed:

  • Airline-contributed fuel consumption data by aircraft type
  • Airline-contributed belly cargo data by aircraft type
  • Cabin configurations, i.e., seats by travel class, by aircraft type from a fleets database
  • Passenger occupancy data (i.e., load factors) from IATA traffic database
  • Flight duration from schedules per route, per aircraft type

Existing validation procedures are used, such as data verification for CORSIA. Additionally, IATA conducts its own statistical validation of all input data received from airlines.

Currently, 74 different (IATA designator) aircraft types are covered in the data model, representing more than 98% of the current global passenger fleet.

​Some elements such as airline fleet information are updated on a monthly basis, while other may be updated annually to ensure sufficient validation processes have taken place. The underlying data may also be updated more frequently if deemed necessary, e.g., when new aircraft types are being introduced and/or when airlines provide individual data submissions on aircraft type fuel burn and cargo payloads.

At present most of the data used is from 2019, as due to COVID-19 data from 2020 and 2021 does not provide an accurate picture. During the course of 2023, operational data from 2022 will be fed into the calculator.

Currently, a single fuel burn rate (kg/min) is used for all flights on a given aircraft type, regardless of its duration. While this causes some loss of accuracy, particularly for flights outside an aircraft’s usual operations (e.g., a widebody used on a very short flight), the impact is marginal, especially after considering other sources of uncertainty in the pre-flight CO2 estimates. Nevertheless, we are considering the use of differentiated fuel burn rates depending on the duration of the flight in a future release of the calculator.

Yes, this feature will be part of a later enhancement to the calculator.

In line with the RP1726, the use of SAF (Sustainable Aviation Fuel) is not considered in the estimates, primarily due to the lack of a globally-accepted accounting framework for SAF use. It is expected that the next revision of the RP1726 will include more detailed guidance on this topic. The calculator will be updated accordingly.

​In line with the RP1726, carbon offsets are not considered in the estimates. 

IATA is closely engaging with ICAO’s Committee on Aviation Environmental Protection (CAEP), research institutions and industry stakeholders to monitor developments in measuring non-CO2 emissions from conventional fuel and SAF. In line with the recommended practice RP1726, RFI and non-CO2 effects are not included in the calculator. As soon as consensus has been reached by the global scientific community in terms of the value(s) that must be applied, the IATA CO2 Connect calculator will be adapted accordingly.

Should you be interested in more background on this topic, please refer to the RP1726 methodology.

​In line with the recommended practice RP1726, the IATA CO2 Connect calculator uses an emissions factor of 3.16 for jet kerosene, which includes the CO2 emissions related to jet kerosene combustion. This is based on ICAO Annex 16, Volume IV. Upstream emissions (i.e., those related to production and transport of the fuel) are therefore not included in the estimates.

Currently it is not possible to calculate cargo CO2 emissions with the IATA CO2 Connect calculator. However, we are working on developing a dedicated cargo CO2 emissions calculator, which we aim to launch in 2023.  


Currently, it is not possible to compensate CO2 emissions via the IATA CO2 Connect calculator. However, we are developing such a solution, and a compensation feature will be added to IATA CO2 Connect calculator in 2023.