Estimate your carbon footprint. This free CO2 footprint calculator turns your annual electricity, gas, driving and flights into tonnes of CO₂e, with a per-source breakdown and context,
This gives a simplified estimate of carbon footprint from a few common sources, using average emission factors. Real figures depend heavily on your country’s electricity grid, vehicle and lifestyle — treat it as a rough guide for awareness, not an audit.
Annual usage
kWh
kWh
km
Enter your annual electricity, gas, driving and flying. Pick the grid intensity and car type that fit best. Leave anything blank to skip it. Flights use passenger-kilometres (distance flown).
Annual carbon footprint
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Enter your usage
Electricity
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Gas
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Driving
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Flights
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Each source = activity × an emission factor: electricity by grid intensity, gas ≈ 0.18 kg/kWh, driving by the car’s g/km, flights ≈ 0.15 kg per passenger-km. Totals are in CO₂-equivalent (CO₂e). A mature tree absorbs very roughly 20 kg of CO₂ a year.
Use this free CO2 footprint calculator to estimate your annual carbon footprint. Enter your electricity, gas, driving and flights to see your tonnes of CO₂e and where it comes from.
What this CO2 footprint calculator does
A carbon footprint calculator multiplies each activity by an emission factor and adds them up. It covers home energy, driving and flying, and reports the total in CO₂-equivalent.
How the footprint is calculated
electricity = kWh × grid intensity
gas = kWh × 0.184
driving = km × car g/km
flights = passenger-km × 0.15
A fairly typical mix — 3,000 kWh electricity, 8,000 kWh gas, 12,000 km driving and 5,000 km flying — comes to roughly 5.5 tonnes CO₂e a year.
Emission factors used
Source
Factor
Electricity
~0.05–0.70 kg/kWh (grid-dependent)
Natural gas
~0.18 kg/kWh
Car (petrol)
~120–250 g/km
Flights
~0.15 kg/passenger-km
Putting it in context
The global average is around 4–5 tonnes per person per year, and many climate targets aim for about 2 tonnes. The biggest levers are usually home heating, car use and flights — and a cleaner electricity grid lowers everything plugged into it.
How to use the CO2 calculator
Enter annual electricity and gas, and pick the grid.
Add driving distance and your car type.
Add flights in passenger-kilometres.
CO2 Footprint FAQ
How is a carbon footprint calculated?
Each activity is multiplied by an emission factor — for example electricity by your grid's kg per kWh, driving by the car's grams per km — and the results are added into CO₂-equivalent.
What's an average carbon footprint?
Around 4–5 tonnes of CO₂e per person per year globally, though it varies widely by country and lifestyle. Many climate targets aim for about 2 tonnes.
Why does the electricity grid matter?
The same kWh produces very different emissions depending on how it's generated — from about 0.05 kg/kWh on a renewable grid to 0.7 on a coal-heavy one.
How much CO2 does a flight produce?
Roughly 0.15 kg per passenger-kilometre, so a 5,000 km flight adds about 750 kg of CO₂e.
How can I reduce my footprint?
The biggest levers are usually home heating, car use and flights — plus switching to a cleaner electricity supply, which lowers everything electric.
Is the CO2 footprint calculator free?
Yes, this CO2 footprint calculator is completely free, needs no sign-up, and gives instant results in your browser.
