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Carbon · Comparison
Flight vs Train CO₂
Enter a route distance and compare emissions across 9 transport modes — flights (with radiative forcing), high-speed rail, coach, solo car, shared car and EV.
Total distance
920 km
Best option (Long-distance coach) emits 24.8 kg CO₂ — the worst emits 226 kg, a 9× difference.
Emissions by mode
🚌Long-distance coach
24.8 kg
🚄High-speed rail
25.8 kg
🚆Regional train
37.7 kg
🚗Car (4 people, petrol)
44.2 kg
🔌EV (solo, 300 g/kWh)
49.7 kg
🚗Car (2 people, petrol)
88.3 kg
✈️Flight (medium-haul)
176.6 kg
🚗Car (solo, petrol)
176.6 kg
✈️Flight (short-haul)
226.3 kg
Formula
CO₂ = distance × factor per passenger-km
Flights include 1.9× radiative forcing multiplier (DEFRA 2024)
Shared car = 192 g/km ÷ occupants
Factors are DEFRA 2024 well-to-wheel values. High-speed rail assumes European grid mix; a Norwegian train would be lower and a Polish one higher — override with your national factor if you need country-specific accuracy.
FAQ
Why is a short-haul flight worse per km than long-haul?
Take-off and landing are disproportionately fuel-intensive. On a 500 km hop that phase is 30–40% of total fuel burn; on a 10,000 km trip it is under 5%. Per passenger-km, short-haul lands around 246 g CO₂e vs 195 g for long-haul.
Do these numbers include radiative forcing?
Yes for flights (×1.9 multiplier per DEFRA 2024) — this captures the additional warming from contrails, NOₓ and water vapour at cruising altitude. Trains, cars and buses have no comparable multiplier.
Why is a full car sometimes better than a train?
Occupancy matters. A petrol car at 192 g CO₂/km carries 4 people = 48 g per passenger-km — better than a regional train (41 g) and close to a high-speed one (28 g). Solo driving in the same car is 4× worse.
What about ferries and cruise ships?
Ferry: 20–120 g CO₂/passenger-km depending on speed and occupancy. Cruise: 250–450 g/passenger-km — comparable to a short-haul flight when normalised. Both are excluded here to keep the comparison focused on point-to-point transit.