Carbon Footprint Calculator — Estimate CO2 Emissions
Estimate your annual carbon dioxide emissions from electricity, natural gas, driving, and air travel. Compare your footprint to the US average. See also our Electricity Cost Calculator and Fuel Cost Calculator.
How to Calculate Your Carbon Footprint
- Enter your monthly electricity usage in kilowatt-hours from your utility bill.
- Enter monthly natural gas consumption in therms.
- Enter the number of miles you drive per month and your vehicle fuel efficiency.
- Enter the number of round-trip flights you take per year.
- Click Calculate to see your annual CO2 emissions breakdown.
Formula
CO2 (lbs/year) =
Electricity: kWh/month × 12 × 0.92 lb/kWh
+ Natural Gas: therms/month × 12 × 11.7 lb/therm
+ Driving: (miles/month × 12 / MPG) × 19.6 lb/gallon
+ Flights: flights/year × 2,200 lb/flightExample
With 900 kWh/month electricity, 50 therms/month gas, 1,000 miles/month at 25 MPG, and 2 flights/year:
Electricity: 900 × 12 × 0.92 = 9,936 lbs
Natural Gas: 50 × 12 × 11.7 = 7,020 lbs
Driving: (1,000 × 12 / 25) × 19.6 = 9,408 lbs
Flights: 2 × 2,200 = 4,400 lbs
Total: 30,764 lbs = 15.4 tons/year
CO2 Emission Factors Reference
| Source | Emission Factor | Unit |
|---|---|---|
| Electricity | 0.92 | lbs CO2/kWh |
| Natural Gas | 11.7 | lbs CO2/therm |
| Gasoline | 19.6 | lbs CO2/gallon |
| Diesel | 22.4 | lbs CO2/gallon |
| Air Travel | 2,200 | lbs CO2/round trip |
| Propane | 12.7 | lbs CO2/gallon |
Frequently Asked Questions
What is a carbon footprint?
A carbon footprint is the total amount of greenhouse gases (primarily CO2) produced by your activities, measured in pounds or metric tons per year.
What is the average carbon footprint in the US?
The average American produces about 16 tons of CO2 per year, which is one of the highest per-capita rates in the world. The global average is about 4 tons.
How can I reduce my carbon footprint?
Switch to LED lighting, improve home insulation, drive a fuel-efficient or electric vehicle, reduce air travel, and consider renewable energy sources like solar panels.
Why does electricity produce CO2?
Most electricity in the US is generated by burning fossil fuels (natural gas, coal). The 0.92 lb/kWh factor is the national average; your local grid may be cleaner or dirtier.
How much CO2 does a flight produce?
A typical domestic round-trip flight produces about 2,200 lbs of CO2 per passenger. International flights can produce 4,000-8,000 lbs depending on distance.