How the estimate works
Each part uses a rounded, widely published emission factor: petrol or gasoline at about 2.3 kg CO2 per litre; grid electricity at the intensity of your region; natural gas at about 0.18 kg per kWh; a short return flight at about 0.25 tonnes and a long return flight at about 1.6 tonnes per passenger; and typical yearly food footprints for each diet. Home energy is divided by the number of people in the household.
How to read your result
The global average is roughly 4.7 tonnes per person per year, and many climate scientists suggest about 2 to 2.5 tonnes per person by 2030 is consistent with limiting warming to 1.5°C. Average per-person figures are much higher in some wealthy countries. The goal is not guilt; it is finding your biggest lever.
The biggest levers for most people
- Transport: drive less, switch to transit, bike, car-share or an electric vehicle; fly less.
- Home energy: insulate, use a heat pump, choose a clean electricity supplier. See Save energy at home.
- Food: eat more plants and waste less food.
- Stuff: buy less, buy second-hand, repair.
Frequently asked questions
Is this calculator accurate?
It gives a reasonable estimate using rounded averages. For an audit you would use your actual bills, vehicle data and purchases.
What is CO2e?
Carbon dioxide equivalent: a way of expressing different greenhouse gases (like methane) in terms of the warming effect of CO2.
Does it include everything I buy?
Only a rough allowance for waste and goods. Manufacturing and shipping of what you buy add more.
Is my data saved?
Only in your own browser so the form is pre-filled next time. Nothing is sent anywhere.