Driving CO₂ Emissions Calculator

How it is calculated

Emissions are the fuel burned multiplied by a per-litre factor: litres = distance × economy / 100 and CO₂ = litres × factor. Distance is in kilometres and economy in litres per 100 km. The factors are 2.31 kg CO₂ per litre for petrol, 2.68 for diesel and 1.51 for LPG; any other fuel value returns no result. Distance can be zero but not negative, and economy must be above zero. The figures count only the carbon dioxide released when the fuel burns in the engine, not the emissions from producing and transporting the fuel. Divide the result by the number of occupants to get a per-person figure.

Common mistakes

• Entering miles per gallon as the economy; it needs litres per 100 km.
• Entering miles for distance, which the tool treats as kilometres.
• Choosing the wrong fuel type, since diesel produces more CO₂ per litre than petrol.
• Comparing a per-vehicle figure with a per-passenger figure for a train or plane.
• Using it for electric or hybrid cars, whose emissions depend on the electricity source and are not modelled.