CO2 Emissions Saved Calculator
See how much carbon dioxide you keep out of the air each year by swapping car trips for an e-bike or e-scooter — with an equivalent in trees to make the number tangible.
CO2 saved per year
How the estimate works
Emissions scale with distance. Multiply the kilometres you ride in a year by a per-kilometre emissions factor and you get the total for each mode; the difference between the car and the micro-mobility figure is what you avoid. Because an e-bike’s charging footprint is a small fraction of a car’s tailpipe output, the saving over a year’s commuting adds up fast.
The tree equivalent turns an abstract kilogram figure into something easier to picture, using the common estimate that one mature tree absorbs about 21 kg of CO2 a year.
Frequently Asked Questions
How is the CO2 saving calculated?
For each mode the tool multiplies your annual distance by an emissions factor in grams of CO2 per kilometre, then converts to kilograms. The saving is the car's yearly emissions minus the e-bike or e-scooter's. Riding 5,000 km a year at a car's 170 g/km instead of an e-bike's 8 g/km avoids roughly 810 kg of CO2.
Do e-bikes and e-scooters really produce emissions?
Riding them produces none directly, but charging the battery draws electricity that may have been generated with some fossil fuel, and manufacturing has a footprint too. On an average grid the charging footprint is only a few grams of CO2 per kilometre — a small fraction of a car's — which is why the net saving is so large. On a clean grid it is smaller still.
What does the 'equivalent trees' figure mean?
A mature tree absorbs very roughly 21 kilograms of CO2 per year, so we divide your annual saving by that to give an intuitive comparison. It is a rough illustration rather than a precise accounting figure — real uptake varies enormously by species, age, and climate.
What emissions factor should I use for my car?
The 170 default is grams per kilometre, counted at the tailpipe: what a petrol car using about 7.2 litres per 100 km emits. Work out your own car's figure from its fuel economy: 2,347.7 divided by its km per litre gives g/km, and 8,887 divided by its miles per gallon gives g/mile (EPA's grams of CO2 per litre and per US gallon of gasoline). EPA puts its average US passenger vehicle at about 400 g per mile. If you share the car, set the number of people in it: car emissions are per vehicle, so a carpooler's share is smaller.
Educational estimate only. Emissions factors vary by vehicle, grid, and method; the tree figure is a rough illustration, not a certified offset.