Interactive Tool
Choose a route — or enter any trip distance — and see the carbon difference between taking the train and flying. Honest, source-backed averages, no greenwashing.
The calculator multiplies your trip distance by published per-passenger-kilometre CO₂ emission averages for rail and for air travel, then shows the kilograms of CO₂ for each, the absolute amount saved, and the percentage reduction. A second line translates the saving into a familiar yardstick: roughly how far you'd drive an average petrol car to emit the same amount.
The emission factors come from the UK Government's (DESNZ) greenhouse-gas conversion factors — compiled by Our World in Data — and the European Environment Agency, the same tier of source we cite for the night-train comparisons elsewhere on the site. They are directional averages, not a certified per-trip measurement: real numbers move with the specific train (a fully electrified high-speed line like Eurostar is far cleaner than a diesel branch line), the aircraft, and how full both are.
Convinced the train wins? These guides help you actually book it.