Green Commute CO₂ Calculator
Compare CO₂ emissions across different commute modes for a given distance and frequency.
Inputs
About Green Commute CO₂ Calculator
Average car emissions
EPA reports average passenger vehicle emits ~404g CO₂/mile (~0.89 lb/mi). Real-world ranges 200-600g/mi depending on size, efficiency, driving style.
EVs are not zero
EVs emit ~110g CO₂/mile in the US grid mix on average (much less in WA/CA hydro/solar regions). 30-70% lower than gas cars, but never zero unless powered by 100% renewable.
Best mode
Walking/biking is zero direct emissions. Public transit cuts per-passenger emissions ~50-70% vs solo driving. Carpooling 2x = halve the per-person impact.
Why the suggested swap isn't always a bike
Bike or walk is only offered as the suggested alternative when the one-way trip is 5 miles or less — past that it stops being a realistic daily commute for most people, so the tool suggests the cleanest option that is (train, bus, EV or hybrid). Every mode, bike included, is still charted at your distance in the "Compare modes" tab.
How gasoline saved is counted
Gallons are measured against a 25 mpg gas car covering the same miles. A 50 mpg hybrid saves about half of them and still burns the rest; an EV, bus, train, bike or walk buys none at the pump. If you already drive a 25 mpg gas car there is nothing to save, so the tile shows the gallons you burn instead.
Modes are alternatives, not a pie
You commute one way, not six, so this tool never shows the modes as slices of a single total. The "Your footprint" tab gives your mode's own annual CO₂ plus the saving from one realistic switch; "Compare modes" puts all six side by side at the same distance.