Flight CO2 Emissions Calculator

Combustion stoichiometry: jet fuel is roughly 86% carbon by mass, each carbon atom binds two oxygens from the air, and the mass ratio works out near 3.16 — the factor ICAO adopted for CORSIA. Avgas runs marginally lower (~3.10). The CO2 outweighing the fuel surprises people; the oxygen came from the atmosphere, which is also why there's no clever combustion fix — the factor is the fuel's chemistry, and reductions come from burning less or burning SAF whose production absorbed carbon.

Divide by passengers — and then defend your choices: total flight CO2 over actual occupants is honest for a charter; airline-style accounting allocates between cabins by space, splits freight's share, and uses network load factors, which is why public calculators disagree by multiples for the 'same' route. For business reporting, state the method (total fuel × 3.16, divided by actual pax) and the number is defensible; chasing precision beyond that buys argument, not accuracy.

No — and that's the right mental model: combustion emitted what it emitted. Offsets compensate elsewhere; SAF's benefit is lifecycle (production absorbed carbon the flame re-releases), credited per pathway certificates rather than at the exhaust. Carbon reporting therefore typically shows gross emissions (this calculator), then reductions from SAF attributes and offsets as separate lines. The SAF blend calculator on this site does that second line's math.

No account and no connection are needed once the page has loaded — records live in local storage on your device and every calculation runs in your browser. Data doesn't sync between devices, so export the CSV when you want to move or archive your records.

Always — the CSV export is a complete, lossless dump of your emissions estimate, generated locally in one click. Import it into commercial software, archive it with your files, or post-process it in a spreadsheet. No lock-in is deliberate: data you can't take with you isn't really yours.