How much CO2 does a car produce per mile?

A typical petrol car produces around 170-200g of CO2 per kilometre (about 270-320g per mile). This varies greatly with fuel type, engine size, and efficiency. Diesel produces more CO2 per litre burned but is often more fuel-efficient. EVs produce zero tailpipe emissions but have indirect emissions from electricity generation.

How does the UK compare globally for car emissions?

The average UK car produces about 2.4 tonnes of CO2 per year. The UK average annual mileage is about 7,400 miles. The UK government target is to reach net zero by 2050, with a ban on new petrol and diesel car sales from 2035.

Are electric cars really better for the environment?

Yes, even accounting for electricity generation and battery manufacturing. In the UK, an EV produces about 50-70% less CO2 over its lifetime than a petrol car. As the grid gets cleaner (more renewables), this advantage increases. The break-even point where an EV becomes cleaner than a petrol car is typically 20,000-30,000 miles.

How can I reduce my car's carbon footprint?

Drive less (combine trips, car share, use public transport), drive efficiently (smooth acceleration, anticipate traffic, correct tyre pressures), maintain your car well, consider a more efficient or electric vehicle, and offset remaining emissions through verified schemes.

What does it mean to offset carbon emissions?

Carbon offsetting means compensating for your CO2 emissions by funding projects that remove or prevent an equivalent amount of CO2, such as tree planting, renewable energy, or methane capture. One mature tree absorbs about 22kg of CO2 per year. Offsetting is not a substitute for reducing emissions but can complement other efforts.

CarCalcs

Carbon Footprint Calculator — Car CO2 Emissions

Calculate the CO2 emissions from your car based on annual mileage, fuel type, and efficiency.

Annual Mileage

Fuel Economy

For EVs, enter equivalent MPG or leave at default

Fuel Type

Regular Passengers (incl. driver)

How We Calculate This

How CO2 Emissions Are Calculated

Calculate annual fuel consumption: Annual mileage / MPG x 4.546 = litres
Multiply litres by CO2 factor: Petrol = 2.31 kg/litre, Diesel = 2.68 kg/litre
For EVs: Miles x 0.3 kWh/mile x 0.233 kg CO2/kWh (UK grid average)
Divide by number of regular passengers for per-person figure

Offsetting

One tree absorbs approximately 22 kg of CO2 per year. One short-haul flight (e.g., London to Edinburgh) produces approximately 150 kg of CO2 per passenger.

Frequently Asked Questions

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Last updated: February 2026

All calculations are estimates. Actual figures may vary based on driving conditions, vehicle specifications, and other factors.