Miles Driven to CO₂ Calculator
Convert miles driven in a car into estimated carbon emissions (kg CO₂e). Enter a distance to see the result and how it is worked out.
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How it's calculated
The selected input unit is first converted to miles, then the calculation is a single multiplication:
kg CO₂e = distance driven (miles) × 0.393 (kg CO₂e per mile)
Emission factor: 0.393 kg CO₂e per mile. Source: US EPA, average gasoline passenger vehicle (2022 activity data). Boundary: Vehicle use; excludes fuel production and vehicle manufacture. Factor vintage: 2022.
Accuracy and limitations
- This is the EPA average for a US gasoline passenger vehicle, not a factor for every car or country.
- It includes tailpipe CO₂, methane and nitrous oxide, but excludes fuel production, road construction and vehicle manufacture.
- For a known gasoline car, a fuel-used calculation based on actual consumption is usually more accurate than an average-per-mile factor.
Frequently asked questions
How do you convert miles driven to CO₂?
Multiply the distance driven (in miles) by an average emission factor in kg CO₂e per mile. The factor reflects a typical passenger car; a more efficient or electric vehicle emits less.
Does the type of car matter?
Yes. This uses an average passenger-vehicle factor. A small hybrid emits far less per mile than a large SUV, and an EV’s emissions depend on the electricity grid rather than fuel burned.
Is this suitable for an electric or hybrid car?
No. The factor represents an average gasoline passenger vehicle. Use the EV vs petrol calculator for an EV, or calculate a gasoline car from actual fuel consumed when you have that data.