Ecological Footprint Calculator
Estimate your annual carbon footprint in tonnes of CO₂ and how many Earths your lifestyle would need, from driving, home electricity, flights and diet.
How it works
Footprint = driving×0.192 + electricity×12×0.40 + flying×90 + diet factor (kg CO₂e) · Planets = tonnes ÷ 2.9 (per-person carbon biocapacity share)
This simple footprint totals the carbon dioxide equivalent from the four biggest household levers — car travel, home electricity, air travel and diet — using representative average emission factors. Converting to 'planets' compares your annual emissions to the share of the Earth's biocapacity available per person if we shared it equally, so anything above one planet is unsustainable if universal. The estimate is deliberately rough: real footprints vary with your car, local grid mix, aircraft and food sources, so treat it as a directional guide rather than a precise audit.
Worked example
Driving 12,000 km (2.30 t) + 400 kWh/month × 12 × 0.4 (1.92 t) + 10 flight-hours (0.90 t) + an average diet (2.50 t) totals about 7.62 t CO₂e a year, or roughly 7.62 ÷ 2.9 ≈ 2.6 Earths.
Sources: Ecological footprint — Wikipedia
Frequently asked questions
How accurate is this estimate?
It uses global-average emission factors, so it captures the right order of magnitude and shows which activities dominate your footprint, but it is not a precise inventory. A detailed audit would use your exact vehicle, local grid carbon intensity and specific flights.
What does "number of Earths" mean?
It compares your annual carbon emissions to the roughly 2.9 tonnes of CO₂ per person that the biosphere can absorb sustainably each year. Two Earths means your lifestyle, if everyone adopted it, would need twice the planet we have.
Which change cuts a footprint the most?
For most people flying and a meat-heavy diet are the largest discretionary items, followed by car mileage. The breakdown here shows exactly which of your four categories is biggest so you can target it.
Related calculators
This calculator is for educational purposes. Double-check important results before acting on them.