Travel Carbon Calculator

Where do the emission factors come from?

From a table in the tool’s code, in kilograms of CO₂ per kilometre: short-haul flight 0.255, long-haul flight 0.195, economy car 0.192, electric car 0.053, train in Europe 0.041, train in the US 0.086, coach or bus 0.089, motorbike 0.114 and cruise ship 0.245. The code does not cite a source for them, and emission factors vary by year, region, vehicle load and method, so treat them as the tool’s fixed estimates.

Do the passengers change the total or the per-person figure?

It depends on the mode. For a car, electric car or motorbike the factor is per vehicle, so more passengers share the same total: 1,000 km in an economy car with 4 people is 192.0 kg in total and 48.0 kg each. For flights, trains, coaches and cruises the factor is per passenger, so total CO₂ rises with passengers and the per-person figure stays the same.

What does "vs driving the same distance" compare?

Your CO₂ per passenger against the same number of people sharing one economy car over the same distance. Flying 1,000 km short-haul alone shows 33% more than driving; the train in Europe shows 79% less. If you choose the economy car, it reads "Same CO₂ as driving".

How is the tree figure worked out?

CO₂ per passenger divided by 21 kg, the amount the tool assumes one tree absorbs in a year. A 255 kg short-haul trip gives 12.1 trees. Real absorption varies by species, age and climate, so the number is an illustration of scale rather than a plan for offsetting.

What is "Equivalent Car km"?

The distance an economy car would have to travel, with one occupant, to emit your per-passenger CO₂ at 0.192 kg per km. For the 255 kg flight that is 1,328 km.

What does the calculator not include?

Anything beyond the single factor: non-CO₂ effects of flying, fuel production, cabin class, load factors, vehicle age, speed, the route actually flown or driven, and hotel stays. The long-haul factor is lower than the short-haul one in this table, which is how the tool is built and not a statement about every flight.

Can I compare an electric car in different countries?

No. There is one electric-car factor, 0.053 kg per km, with no adjustment for the electricity mix of a country or charging method. Likewise there is one factor for European trains and one for US trains, nothing country specific.