Flight Emissions Calculator — CO₂e per Passenger
Find out how much CO₂ equivalent your flight produces per passenger. Enter the one-way distance, cabin class and whether you are flying return — the calculator compares the result to driving or taking a train the same distance.
km
Cabin class
Trip type
Carbon dioxide equivalent including radiative forcing at altitude
- 1
Total distance flown
5,000 km × 2 legs = 10,000 - 2
Effective emission rate
0.195 kg/km × 1 (class mult.) = 0.195Long-haul factor (≥ 1,500 km one-way). - 3
Flight CO₂e
10,000 km × 0.195 kg/km = 1,950
How does this calculator work?
Flight CO₂e = distance × legs × emission factor × cabin multiplier. Economy short-haul: 0.257 kg CO₂e/km; long-haul: 0.195 kg CO₂e/km; business class: ×2.4; first class: ×4.0 (2023 DEFRA, including radiative forcing). A typical transatlantic return in economy produces ≈1 000–2 200 kg CO₂e per passenger.
Formula
How this is calculated
Aviation emissions are dominated by jet fuel combustion, but aircraft also produce contrails, water vapour and ozone-depleting gases at altitude, which amplify the climate effect. This is captured by the radiative forcing index (RFI) built into the emission factors: economy short-haul (< 1 500 km) 0.257 kg CO₂e per passenger-km and economy long-haul 0.195 kg CO₂e per passenger-km (2023 DEFRA methodology). Long-haul flights are slightly more efficient per kilometre because the fuel-heavy take-off and climb phases are amortised over a longer cruise. Values are 2023 estimates and will differ by aircraft type and load factor.
Cabin class matters because premium seats occupy more floor space, meaning fewer passengers share the aircraft's total emissions. Compared to economy, business class is allocated a multiplier of 2.4 and first class 4.0 — rough averages that vary by airline and aircraft configuration.
For context, the calculator also shows the equivalent emissions of the same journey by an average petrol car (0.17 kg CO₂e/km) and by EU-average rail (0.041 kg CO₂e/km). Flights typically emit far more per passenger-km than either mode, though the gap narrows for very long distances where driving is impractical.
Frequently asked questions
Premium seats occupy significantly more floor space than economy seats, so the aircraft's total fuel burn is allocated to fewer passengers in the cabin. Business class typically gets a multiplier of about 2.4× and first class about 4× the economy emission factor.
Radiative forcing accounts for the non-CO₂ climate effects of aviation: contrails, water vapour and cirrus cloud formation at altitude amplify the warming effect beyond what CO₂ alone would cause. Including it roughly doubles the CO₂-equivalent figure compared to CO₂-only figures you may see elsewhere.
A rough rule of thumb is that a mature tree absorbs around 21 kg CO₂ per year. For a transatlantic economy return flight (≈5 570 km each way, ≈2 170 kg CO₂e total) you would need roughly 100 tree-years — planting about 10 trees today that grow and absorb carbon for 10 years. Actual sequestration rates vary widely by species, climate and land use.
Also known as
TG we-Calculate Editorial Team. (2026). Flight Emissions Calculator — CO₂e per Passenger [Online calculator]. TG we-Calculate. https://we-calculate.com/calculator/flight-emissions-calculator
TG we-Calculate Editorial Team. "Flight Emissions Calculator — CO₂e per Passenger." TG we-Calculate. 2026. https://we-calculate.com/calculator/flight-emissions-calculator.
TG we-Calculate Editorial Team, "Flight Emissions Calculator — CO₂e per Passenger," TG we-Calculate, 2026. [Online]. Available: https://we-calculate.com/calculator/flight-emissions-calculator
@misc{wecalculate_flight_emissions_calculator, title = {Flight Emissions Calculator — CO₂e per Passenger}, author = {{TG we-Calculate Editorial Team}}, howpublished = {\url{https://we-calculate.com/calculator/flight-emissions-calculator}}, year = {2026}, note = {TG we-Calculate} }
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