Car CO2 Emissions Calculator
Estimate the annual CO₂ output of your car based on how much you drive, your fuel type, and your car's fuel economy.
How to estimate annual car CO2 emissions
Enter annual miles with US MPG, or kilometers with liters per 100 km, and choose gasoline or diesel. The calculator estimates fuel burned and the carbon dioxide produced at the tailpipe. It does not calculate manufacturing or upstream fuel emissions.
CO2 factors and example
This tool uses EPA tailpipe factors of 8.887 kg of CO2 per US gallon of gasoline and 10.180 kg per US gallon of diesel. Annual CO2 equals fuel burned multiplied by the selected fuel factor.
At 12,000 miles per year and 30 MPG, a gasoline car uses 400 US gallons. The estimate is 3,554.8 kg, or 3.55 metric tons of tailpipe CO2 per year.
Car emissions calculator questions
Is this a complete carbon-footprint calculation?
No. It covers fuel combustion at the tailpipe only and excludes vehicle manufacturing, fuel production and other greenhouse gases.
Can I use it for a battery-electric car?
No. Electricity-generation emissions require a different method. This calculator accepts gasoline and diesel consumption.
What is the difference between g/mile and metric tons per year?
Grams per mile describes emission intensity. Metric tons per year combine that intensity with the annual distance driven.