Flight Emissions Calculator
Estimate CO₂ from a flight by distance and passengers.
Results update as you type.
How it works
Air travel is one of the most carbon-intensive things an individual can do per hour, and this flight emissions calculator estimates the carbon dioxide a journey produces from just two inputs: the flight distance in kilometres and how many passengers are travelling. It reports the result in kilograms for a single trip and in metric tons so you can slot it into a yearly carbon budget. The estimate uses a per-passenger-kilometre emission factor that averages the fuel burned across typical aircraft and occupancy. Because emissions scale directly with distance, long-haul flights dominate a traveller's footprint, while short hops add less. Multiplying by passenger count lets a family or group see their combined impact in one figure rather than per seat. Understanding flight emissions matters as more people track and offset their travel. Seeing that a single long-haul return trip can rival an entire year of driving reframes how significant flying is, helping travellers decide whether to fly less, choose direct routes that burn less fuel, or purchase credible offsets. Eco-conscious travellers, event planners weighing venue locations, and students studying transport emissions all use a flight emissions calculator to quantify an otherwise invisible cost and make more informed choices about how they move.
CO₂ (kg) = distance km × 0.115 × passengers
Aircraft burn fuel roughly in proportion to distance flown, and averaged across seat classes and load factors a passenger accounts for about 0.115 kilograms of CO₂ for every kilometre travelled. Multiplying flight distance by that factor gives one traveller's emissions, and multiplying again by the number of passengers scales it to a whole party. Dividing the kilogram figure by 1,000 converts it into the metric tons used for annual carbon budgets.
Source:U.S. EPA greenhouse gas equivalencies
We review all our tools from time to time to ensure accuracy.
Worked example
How to use this calculator
- 1
Enter your values
Enter flight distance and passengers.
- 2
Adjust the options
Fine-tune any options to match your situation.
- 3
Read your result
CO₂ emitted updates instantly as you type — no button to press.
Frequently asked questions
What emission factor does this calculator use?
It applies about 0.115 kilograms of CO₂ per passenger-kilometre, a common average drawn from environmental agency figures for typical commercial flights. This blends different aircraft, seat classes, and load factors into one representative number. Business and first-class seats occupy more space and therefore carry a larger share of the fuel, so premium travel exceeds this average, while a full economy cabin on an efficient jet can come in slightly below it.
Does distance affect emissions per kilometre?
Yes, in practice. Take-off and climb burn disproportionately more fuel, so very short flights emit more per kilometre than long cruises where the aircraft spends most time in efficient level flight. This calculator uses a single average factor for simplicity, so it slightly understates short hops and slightly overstates some long-haul legs. For rough planning the average works well, but dedicated tools that model flight phases give finer detail.
Should I count each leg of a round trip?
Yes. Enter the total distance you actually fly, which for a return journey is roughly double the one-way distance, plus any connecting legs. A traveller flying out and back covers both directions, so both must be included to reflect the true footprint. If you make multiple connections, add up every segment's distance, since each one burns fuel independently regardless of how briefly you stop between them.
Does this include the extra warming from high-altitude emissions?
No. This estimate counts only the carbon dioxide from burning jet fuel. Aircraft also create contrails and emit other gases high in the atmosphere that add further warming, an effect often captured by a radiative forcing multiplier of roughly two to three. If you want a fuller climate impact, multiply the CO₂ figure here accordingly, keeping in mind that the multiplier is an area of active scientific refinement.
How does flying compare to driving the same distance?
For a solo traveller, a long flight and a car trip of similar length can produce broadly comparable CO₂, but flights cover vastly greater distances in a day, so total trip emissions are usually far higher. A single intercontinental return flight can match or exceed an average car's entire year of emissions. Sharing a car spreads its footprint across passengers, whereas each air passenger already carries their allocated share.