Driving Carbon Footprint Calculator
Calculate the estimated CO₂ emissions from your driving, based on miles driven and your vehicle's fuel economy.
How this estimate is calculated
This calculator uses standard emission factors: burning one gallon of gasoline produces roughly 8.887 kg of CO₂, while diesel produces roughly 10.180 kg per gallon (diesel is denser and contains more carbon per gallon, despite often getting better fuel economy). Your total gallons used is estimated from miles driven divided by fuel economy, then multiplied by the appropriate emission factor.
This measures only tailpipe emissions from fuel combustion — it doesn't include the 'upstream' emissions from extracting, refining, and transporting the fuel itself, or emissions from vehicle manufacturing, which would make a full lifecycle footprint somewhat higher than this driving-only estimate.
Putting your driving footprint in context
Vehicle emissions are one of several major contributors to a typical household's overall carbon footprint, alongside home energy use, air travel, and diet — reducing driving emissions (through more fuel-efficient vehicles, reduced mileage, or alternative transportation) is one lever among several for those looking to reduce overall environmental impact.
Fuel economy has an outsized effect on this calculation — an inefficient vehicle at 15 MPG produces roughly double the emissions of an efficient one at 30 MPG for the same distance driven, which is why fuel efficiency ratings are commonly highlighted in vehicle environmental comparisons.
Frequently asked questions
Does this include emissions from manufacturing the fuel itself?
No — this calculates tailpipe emissions from fuel combustion only. A full lifecycle assessment would also include upstream emissions from extracting, refining, and transporting the fuel, which would push the total somewhat higher.
Why does diesel have a higher emission factor than gasoline per gallon?
Diesel fuel is denser and contains more carbon per gallon than gasoline, so burning it produces more CO₂ per gallon — even though diesel engines often achieve better fuel economy, which can partially offset the difference in overall emissions.