Flight Carbon Emissions Calculator
Estimate the carbon footprint of a flight for each passenger. Choose two airports or type the distance, pick your cabin class and whether it is a round trip, and see the CO2 and CO2-equivalent emissions with everyday comparisons.
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Warming from contrails and NOx at altitude, applied as a multiplier on CO2.
Real flights fly further than the great-circle line.
Optional: your own kg CO2 per passenger-km for economy. Blank = defaults below.
How to use the Flight Carbon Emissions Calculator
- Choose your airports, or switch to Enter distance and type the one-way flight distance.
- Pick the cabin class, the number of passengers and whether it is a round trip.
- Choose how to count non-CO2 effects, or leave the common ×1.9 multiplier.
- Press Calculate emissions to see CO2e per passenger and for the group.
- Compare cabin classes in the table, or enter an airline's own factor for a closer estimate.
The calculation and its default factors
- Distance flown = great-circle distance × (1 + routing extra), × 2 for a round trip
- CO2 per passenger = distance flown × economy factor × cabin seat-space factor
- CO2e per passenger = CO2 × non-CO2 multiplier
- Jet fuel = CO2 ÷ 3.16 (kg of CO2 per kg of fuel); 1 liter of jet fuel weighs about 0.8 kg
The default economy factors are FreeToolCabin estimates based on typical fuel burn per seat for modern airliners at typical load factors. They are averages for planning and comparison, not airline-specific figures, and you can replace them with your own factor.
| Flight length | Economy factor (kg CO2 per passenger-km) | Premium economy | Business | First |
|---|---|---|---|---|
| Short-haul, under 1,500 km | 0.130 | ×1.2 | ×1.5 | ×2.0 |
| Medium-haul, 1,500–4,000 km | 0.100 | ×1.2 | ×1.5 | ×2.0 |
| Long-haul, over 4,000 km | 0.085 | ×1.6 | ×2.9 | ×4.0 |
Example: New York JFK to London Heathrow is about 5,540 km. With 8% routing extra a round trip is about 11,970 km. In economy that is 11,970 × 0.085 ≈ 1,017 kg of CO2, or about 1.93 tonnes CO2e with the ×1.9 multiplier.
Ways to lower the footprint of a trip
- Fly economy. On long-haul flights it has roughly a third of the footprint of business class.
- Fly direct. Every extra take-off and detour adds fuel burn.
- Pack light. Less weight means less fuel, especially on long flights.
- Take the train for short trips. Under about 500 km, rail is often similar in door-to-door time and far lower in emissions.
- Take fewer, longer trips rather than several short ones.
Frequently asked questions
How are flight emissions calculated?
The calculator takes the great-circle distance between the airports, adds a routing extra (8% by default) because planes do not fly in perfectly straight lines, and multiplies by an emission factor in kg of CO2 per passenger-kilometre for the flight length and cabin class. A multiplier can then be applied for non-CO2 warming effects.
Why does business class have a bigger footprint?
Emissions are shared out by the floor space a seat takes up. A long-haul business seat with a lie-flat bed takes roughly three times the space of an economy seat, so it is allocated roughly three times the emissions, even though the plane burns the same fuel.
What does CO2e mean and what is the non-CO2 multiplier?
CO2e (carbon dioxide equivalent) expresses all warming effects as the amount of CO2 that would cause the same warming. At cruising altitude, contrails and nitrogen oxides add warming beyond the CO2 from burning fuel. Methods handle this with a multiplier on CO2, commonly between about 1.7 and 3; research is still refining the exact value.
Why are short flights worse per mile?
Take-off and climb burn a lot of fuel, and on a short flight that is spread over fewer miles. Short routes also tend to use smaller, less efficient aircraft, so the emissions per passenger-kilometre are higher than on long flights.
How much CO2 does burning jet fuel produce?
Burning 1 kg of jet fuel (kerosene) produces about 3.16 kg of CO2, because each carbon atom in the fuel combines with oxygen from the air. The calculator uses this to show how much fuel your seat accounts for.
How accurate is this estimate?
It is a reasonable average. Real emissions depend on the aircraft type, how full the plane is, the cargo carried, the route flown and weather. Airline- or flight-specific figures can differ by 20% or more, so use the custom factor if you have a better number.
Are all the tools on FreeToolCabin tested for quality and accuracy?
Yes! Every tool on our site undergoes automated Q/A testing in real browser environments to ensure high precision, correct output, and zero errors. If you happen to spot a bug or have a suggestion, please contact us at [email protected] and our team will review it right away.