Carbon Footprint Calculator
Household CO₂ a year
11.9 t
5.9 t per person across 2 people. From home energy and travel only; the U.S. average for all energy use is about 14 t of CO₂ per person and the world average about 4.7 t.
- Electricity4.0 t
- Natural gas3.2 t
- Heating oil and propane0.0 t
- Driving3.8 t
- Flights0.9 t
CO₂ factors per unit: 5.3 kg per therm of gas, 10.21 per gallon of heating oil, 5.72 per gallon of propane, 8.89 per gallon of gasoline, 10.18 per gallon of diesel and 0.15 per passenger-mile flown (EPA). Food, goods and services, often half of a personal footprint, are not included.
Estimate your household's yearly CO₂ emissions from home energy and travel: electricity at your grid's carbon intensity, natural gas, heating oil and propane, driving and flying, with each source's share and the result per person, using EPA emission factors.
Formula
Worked Example
Electricity: 10,800 kWh × 0.37 = 4.0 t. Driving: 12,000 ÷ 28 = 429 gallons × 8.89 kg = 3.8 t. Gas: 600 therms × 5.3 kg = 3.2 t. Flights add 0.9 t of CO₂, about twice that if contrails and other high-altitude effects are counted.
Frequently Asked Questions
What is the average carbon footprint per person?
From energy use, the U.S. averages about 14 tonnes of CO₂ per person a year and the world about 4.7. Including food, goods and services, personal footprints in rich countries are often 15–20 tonnes of CO₂-equivalent.
How do I find my electricity's carbon intensity?
It depends on your grid's mix of power plants: around 0.37 kg per kWh on average in the U.S., about 0.05 where hydro and nuclear dominate, and 0.8 or more on coal-heavy grids. The EPA's Power Profiler gives the figure for your ZIP code, and a green tariff or rooftop solar lowers it.
What cuts a household footprint the most?
Usually the largest line: switching from a gas furnace to a heat pump, from a gasoline car to an EV or fewer miles, flying less, and choosing cleaner electricity. Small changes such as LED bulbs matter far less than heating, driving and flights.