Car CO₂ Emissions Calculator (Petrol, Diesel, Electric)
Enter distance and fuel economy to estimate your car’s CO₂ emissions.
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Car CO₂ Emissions Calculator (Petrol, Diesel, Electric) by TheCalcTools
How the Car CO₂ Emissions Calculator (Petrol, Diesel, Electric) works
Burning fuel turns its carbon into CO₂. The US EPA gives 8,887 g of CO₂ per gallon of gasoline and 10,180 g per gallon of diesel, which is about 2.35 and 2.69 kg per litre.
An electric car’s emissions depend on the electricity grid. Multiply its consumption by your grid’s carbon intensity, which ranges from under 50 g/kWh to over 700 g/kWh. Manufacturing emissions are not included for either car.
The formula
Worked example
Using the default values shown in the calculator:
| Fuel | Petrol / gasoline (2.35 kg CO₂ per litre) |
|---|---|
| Fuel use (L per 100 km) | 7.5 |
| Distance per year (km) | 15000 |
| Electric car consumption (kWh per 100 km) | 17 |
| Your grid's carbon intensity (g CO₂ per kWh) | 400 |
- 7.5 L/100 km of petrol = 176 g CO₂ per km.
- 15,000 km a year: 2.64 t, against 1.02 t for an EV on a 400 g/kWh grid.
Result:
| CO₂ per km (g) | 176 |
|---|---|
| CO₂ per year (tonnes) | 2.64 |
| Electric car per year (tonnes, charging only) | 1.02 |
| Yearly difference (tonnes) | 1.62 |
| CO₂ per mile (g) | 283 |
Frequently asked questions
Does this include methane and other gases?
No, tailpipe CO₂ only. CO₂ is about 99% of a car’s direct greenhouse gas emissions by EPA estimates.
Sources and further reading
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This calculator gives estimates for information only. Check important results independently before you rely on them. See our disclaimer.