How to use the fuel combustion co2 calculator
- Choose the fuel and enter how much was burned, in US gallons or liters.
- Optionally enter a second amount of the same fuel to compare, such as another car or another trip.
- Optionally enter the miles driven to see grams of CO2 per mile.
- Open the advanced options if you have your own emission factor and want to use it in place of the built-in example.
Formula
Gallons = liters / 3.785411784
CO2 in kg = gallons x kilograms of CO2 per gallon
Pounds = kg / 0.45359237
Grams per mile = kg x 1000 / miles
The built-in factors are examples for the carbon dioxide made by burning the fuel: gasoline 8.89, diesel 10.18, propane 5.72 and kerosene 9.75 kilograms per US gallon.
12 gallons of gasoline
12 gallons x 8.89 kg per gallon = 106.68 kg, shown as 106.7 kg. That is 235.2 pounds, or 0.107 metric tons. The same 12 gallons of diesel gives 12 x 10.18 = 122.16 kg, shown as 122.2 kg.
For 45 liters of gasoline the tool first converts to 11.888 gallons and the result is 105.7 kg. Comparing 14 gallons with 9 gallons over a 350 mile trip gives 124.5 kg and 80.0 kg, a difference of 44.5 kg, and the first car releases 356 grams per mile.
What the number includes
Burning a gallon of fuel releases a fixed amount of carbon dioxide because the carbon in the fuel combines with oxygen. That is why a simple factor per gallon works well for the tailpipe. It does not include the emissions from drilling, refining and delivering the fuel, which a full life-cycle estimate adds. It also leaves out other gases and the effect of ethanol or other blends, which change the factor a little.
Using your own factor
If your fuel supplier, your country's agency or a vehicle report gives a factor, enter it in the advanced box and the tool will use it. The factor must be in kilograms of CO2 per US gallon, so convert if your source uses liters or another unit. The page shows when a result used the built-in example.
To compare running costs of cars, see the Fuel Cost Calculator and the MPG Calculator. The Fuel Economy Unit Converter switches between miles per gallon and liters per 100 kilometers, and the Road Trip Fuel Stops Calculator plans a drive. The Hybrid vs Gas Break-Even Calculator looks at savings in money.
Assumptions and limits
- The factors are examples and vary a little with the fuel blend and the source.
- Only the carbon dioxide from burning the fuel is counted.
- Gallons are US gallons. A liter figure is converted with 3.785411784 liters to the gallon.
- The second amount uses the same fuel and factor as the first.
Frequently asked questions
Why does diesel give more CO2 than gasoline per gallon?
A gallon of diesel holds more carbon than a gallon of gasoline, so burning it releases more carbon dioxide, even though diesel engines often use fewer gallons.
Are the built-in factors exact?
They are examples. Different sources round them differently, and blends change them, so use your own factor if you have a source for it.
Can I enter fuel in imperial gallons?
Convert to US gallons or liters first. An imperial gallon is about 4.546 liters.
Does this include electricity or heating oil?
No. It covers gasoline, diesel, propane and kerosene, and you can enter a factor of your own for any other fuel that is measured in gallons.