Gallons of Gas to CO₂ Calculator
Convert gallons of gasoline burned into estimated carbon emissions (kg CO₂). Enter a fuel amount 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 US gal, then the calculation is a single multiplication:
kg CO₂ = gasoline burned (US gal) × 8.89 (kg CO₂ per US gallon)
Emission factor: 8.89 kg CO₂ per US gallon. Source: US EPA, motor gasoline combustion. Boundary: Combustion only; excludes fuel production. Factor vintage: 2024.
Accuracy and limitations
- The EPA factor is for a US gallon. UK gallons and litres are converted exactly before the factor is applied.
- This is combustion CO₂ only. It excludes extraction, refining, distribution, methane, nitrous oxide and vehicle manufacture.
- Fuel density and biofuel content vary slightly, so use a supplier-specific factor for formal reporting.
Frequently asked questions
How much CO₂ does a gallon of gas produce?
Burning one US gallon of gasoline releases a fixed amount of CO₂ determined by its carbon content. Multiply gallons burned by that per-gallon factor to get total emissions.
Is this well-to-wheel or just combustion?
The figure shown is a combustion factor (CO₂ released when the fuel is burned). Well-to-wheel factors, which include extraction and refining, are higher — check the source note for which one you are using.
Are US and UK gallons the same?
No. One imperial (UK) gallon is about 1.20095 US gallons. Choose the correct unit; the calculator converts UK gallons and litres to the US-gallon basis used by the EPA factor.