Driving Carbon Footprint Calculator
Find the CO₂ emissions from your annual driving.
Gasoline ≈ 8.887 kg/gal
Results update as you type.
How it works
Driving is a major source of personal carbon emissions, and this calculator estimates yours. You enter your annual miles, your vehicle's fuel economy, and the CO₂ emitted per gallon of fuel, and it returns your annual carbon dioxide emissions in kilograms and tonnes plus the gallons of fuel burned. The calculation is direct: your miles divided by your miles per gallon gives the gallons you burn in a year, and each gallon of gasoline releases about 8.887 kilograms of CO₂ when combusted, a figure set by the carbon content of the fuel. The result reveals the climate impact of your driving, which for a typical car and mileage often amounts to several tonnes of CO₂ per year, a substantial share of an individual's carbon footprint. Seeing the number can motivate lower-carbon choices: driving less, combining trips, carpooling, choosing a more fuel-efficient or electric vehicle, or using public transit, cycling, or walking. Improving fuel economy has a direct proportional effect, so a car that gets twice the miles per gallon emits half the CO₂ for the same distance. The default of 8.887 kilograms per gallon is the standard value for gasoline; diesel emits more per gallon, around 10.18 kilograms, so adjust the figure for diesel vehicles. This estimate covers tailpipe emissions from fuel combustion, not the emissions from producing the fuel or the vehicle. Enter your miles, fuel economy, and CO₂ per gallon to find your driving footprint.
CO₂ = (annual miles / MPG) × CO₂ per gallon
Burning a gallon of gasoline releases about 8.887 kilograms of carbon dioxide. Dividing your annual miles by your fuel economy gives the gallons burned, and multiplying by the CO₂ per gallon gives your annual driving emissions, which the calculator also converts to metric tonnes.
Source:EPA emission factors
We review all our tools from time to time to ensure accuracy.
Worked example
How to use this calculator
- 1
Enter your values
Enter annual miles driven and fuel economy.
- 2
Adjust the options
Adjust co₂ per gallon if they apply — sensible defaults are already set.
- 3
Read your result
Annual CO₂ updates instantly as you type — no button to press.
Frequently asked questions
How much CO₂ does driving produce?
It depends on your mileage and fuel economy. Burning one gallon of gasoline releases about 8.887 kilograms of CO₂, so a car driven 12,000 miles a year at 25 miles per gallon emits roughly 4.3 tonnes annually. The calculator computes your specific emissions from your miles, fuel economy, and the CO₂ per gallon.
Why is a gallon of gasoline about 8.887 kg of CO₂?
The figure comes from the carbon content of gasoline. When burned, the carbon in the fuel combines with oxygen to form carbon dioxide, and each gallon of gasoline produces about 8.887 kilograms of CO₂. Because CO₂ is heavier than the fuel itself (it includes oxygen from the air), the mass of CO₂ exceeds the mass of the gasoline burned.
How can I reduce my driving emissions?
Drive fewer miles by combining trips, carpooling, or using transit, cycling, and walking. Improve fuel economy through smooth driving, proper tire pressure, and reduced idling, or switch to a more efficient hybrid or electric vehicle. Since emissions are proportional to fuel burned, both driving less and burning less per mile cut your footprint directly.
Does this include electric vehicles?
No, this calculator is for fuel-burning vehicles and uses fuel economy in miles per gallon. Electric vehicles have no tailpipe emissions, but their footprint depends on the electricity source used to charge them, which varies by region. For an EV, you would instead estimate emissions from its electricity consumption and the grid's carbon intensity.
What about diesel or other fuels?
Diesel emits more CO₂ per gallon than gasoline, about 10.18 kilograms, because it is denser and more carbon-rich, though diesel engines are often more efficient. To calculate diesel driving emissions, change the CO₂ per gallon value to about 10.18. The calculator lets you adjust this figure for different fuels to get an accurate result.