Car CO₂ Emissions Calculator
Estimate the CO₂ produced by driving a petrol car.
See the carbon impact of a car journey based on its fuel consumption.
How the Math Works
The Car CO₂ Emissions Calculator uses the formula CO₂ = distance/100 × L/100km × CO₂ per litre to estimate emissions. First, divide the total driving distance (in kilometers) by 100 to normalize the calculation. Multiply this by the car's fuel consumption rate (liters per 100km) to find total fuel used. Finally, multiply by the CO₂ emitted per litre of petrol (typically 2.31 kg/L) to convert fuel usage into carbon dioxide emissions. This gives the total CO₂ produced in kilograms or tonnes for the journey.
Practical Applications
To use this calculator, input three values: the distance you plan to drive, your vehicle's fuel efficiency (L/100km), and the CO₂ emission factor per litre of petrol. For example, driving 300 km in a car that uses 8 L/100km would calculate as (300/100) × 8 × 2.31 = 55.44 kg of CO₂. These inputs are typically available in your car's manual, fuel receipts, or online databases for common vehicles.
Day-to-Day Use
By calculating your car's CO₂ emissions, you can make informed decisions to reduce your environmental impact. This helps compare fuel efficiency between vehicles, estimate costs for eco-friendly alternatives, or track your carbon footprint over time. Understanding emissions also supports personal goals like lowering greenhouse gas contributions, participating in environmental initiatives, or justifying investments in more efficient transportation options for daily commutes.
Worked example
100 km at 7 L/100km → 7 L × 2.31 = 16.2 kg CO₂.
FAQ
What about electric cars?
Their footprint depends on the electricity mix — zero tailpipe, but not zero overall.