Travel footprint
This travel carbon calculator measures the CO2e emissions of your flights, rail journeys, car trips, buses and taxis using the UK government's DESNZ 2026 conversion factors. Flight emissions are computed from the great-circle distance between airports plus the DEFRA-prescribed 8% routing uplift, with radiative forcing included by default.
TL;DR — Enter your journeys; we apply official DESNZ 2026 emission factors per transport mode, server-side, and show a total in tonnes of CO2e you can compare against the UK average.
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Running total: 0.00 tCO2e
Flights
Add your round trips by airport.
Flight
Airport to airport, cabin class and passengers
How is it calculated?
- Flights: great-circle distance between airports (haversine) + 8% uplift, then a haul-and-cabin factor from DESNZ 2026 with radiative forcing (RF 1.7) included — e.g. long-haul economy 0.11704 kgCO2e per passenger-km.
- Rail: DESNZ 2026 national rail factor, 0.03092 kgCO2e per passenger-km.
- Cars: DESNZ 2026 factors by car size; average car (unknown fuel) is 0.16591 kgCO2e per km.
- Buses, coaches, London Underground and taxis each use their own DESNZ 2026 per-passenger-km factor.
Every calculation runs server-side against a versioned official factor set and records the factor behind each line — see our methodology.
Frequently asked questions
- How are flight emissions calculated?
- We compute the great-circle distance between your airports, add the 8% uplift DEFRA prescribes for real-world routing, classify the flight as domestic, short-haul or long-haul, and multiply by the DESNZ 2026 factor for that haul and cabin class with radiative forcing included.
- What is radiative forcing and is it included?
- Radiative forcing accounts for the additional warming effect of aviation emissions released at altitude. The UK government recommends including it; DESNZ 2026 uses a multiplier of 1.7, and our flight factors include it by default.
- How much CO2e is a London to New York return flight?
- Roughly 1,400 kg CO2e per passenger in economy, derived from DESNZ 2026 long-haul factors with radiative forcing applied to the great-circle distance plus 8%.