Flight route emissions calculator
Calculate the carbon footprint
of any flight route.
Enter two airport codes. Decarb calculates the great circle distance, applies ICAO fuel burn factors, and shows estimated CO₂e — with and without radiative forcing.
Route
0.000
tons CO₂e
ICAO methodology · Great circle distance · CO₂ only
Calculation breakdown
Total climate impact including radiative forcing (RFI)
At cruising altitude, aircraft emit contrails, nitrogen oxides, and water vapour that create additional warming beyond CO₂ alone. The radiative forcing index (RFI) captures this total climate effect. According to Lee et al. (2021, Atmospheric Environment), the best-estimate RFI multiplier is 1.9–2.7×. The ICAO calculator reports CO₂ only for cross-modal comparability — Decarb shows both figures so you have the complete picture. These are estimated ranges, not verified measurements.
What this means in context
Methodology: Great circle distance computed from airport coordinates. Fuel burn factors by distance band: <1,500 km → 0.255 kg CO₂/km, 1,500–4,000 km → 0.195 kg CO₂/km, >4,000 km → 0.148 kg CO₂/km (ICAO CEC methodology, Doc 9889). Class multipliers: economy ×1.0, premium economy ×1.6, business/first ×2.0 (seat area allocation, ICAO Doc 9889). Return trips apply ×2 distance.
RFI range 1.9–2.7× from Lee et al. (2021), “The contribution of global aviation to anthropogenic climate forcing for 2000 to 2018”, Atmospheric Environment. Actual emissions vary by aircraft type, load factor, routing, and weather. Full methodology: decarb.co/methodology
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Flights are one part of your footprint.
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