Flight Carbon Footprint Calculator
Calculate the CO₂ emissions from your flight in kg and tonnes.
Compare economy vs. business class and see real-world equivalents for your carbon footprint.
How It Works
Aviation accounts for roughly 2–3% of global CO₂ emissions — but when high-altitude warming effects are included, its total climate impact is estimated to be 2–4 times higher. This calculator uses emission factors consistent with those published by the UK government’s Department for Energy Security and Net Zero (DESNZ) and similar bodies.
Base emission factor: The core formula for economy class (including radiative forcing) is approximately 0.255 kg CO₂ per passenger per kilometer. This accounts for fuel burn, aircraft type averages, and the radiative forcing multiplier.
What is Radiative Forcing (RF)? Aircraft emit not just CO₂ but also water vapor, nitrogen oxides, soot, and contrail-forming condensation. At cruising altitude (30,000–40,000 feet), these non-CO₂ effects are estimated to cause additional warming equivalent to roughly 1.9× the CO₂ alone. Including RF gives a more complete picture of aviation’s climate impact. Some calculators omit it — we offer both options.
Cabin class multipliers: Business and first class passengers occupy more space per person, meaning fewer seats per aircraft and higher emissions per passenger.
| Class | Multiplier | Reason |
|---|---|---|
| Economy | ×1.0 | Baseline |
| Premium Economy | ×1.6 | More space, fewer seats |
| Business | ×2.9 | Flat beds, much larger footprint |
| First Class | ×4.0 | Private suites, extreme space use |
Unit conversion: 1 mile = 1.60934 km.
Everyday equivalents (approximate):
- Driving a typical petrol/gasoline car emits ~0.21 kg CO₂ per km
- One week of average home electricity use ≈ 50 kg CO₂
- One tree absorbs approximately 20–25 kg CO₂ per year
Comparing transport modes (economy class, per passenger per km):
| Mode | CO₂ per km |
|---|---|
| Long-haul flight | ~0.13–0.16 kg (CO₂ only) |
| Short-haul flight | ~0.20–0.30 kg |
| Car (petrol, solo) | ~0.17–0.21 kg |
| Train (electric) | ~0.03–0.06 kg |
| Coach / Bus | ~0.03–0.07 kg |
Carbon offset programs: Many airlines and third-party programs offer offset options — planting trees, funding renewable energy projects, or capturing methane. The effectiveness of these varies widely. Independent offsetting through verified programs (Gold Standard, Verra VCS) is generally considered more reliable than airline-provided options.