Free tools / Carbon Footprint Calculator
Carbon Footprint Calculator
Estimate the carbon dioxide from your home energy, driving, and flying using U.S. EPA emission factors — and see which part of your footprint is the biggest.
What this covers — and what it doesn't. This estimates the emissions from energy you use directly: electricity, heating fuel, your car, and flights. It leaves out food, shopping, services, and the emissions from producing and delivering fuel, so a full personal footprint is higher. Treat the result as a useful estimate, not an audit.
Carbon footprint calculator
Your home
Your driving
Your flying
How many miles is my flight?
- Count each direction — a round trip is two flights.
- Examples: New York–Boston is about 190 miles (short), New York–Chicago about 740 (medium), and New York–Los Angeles about 2,450 (long).
- Add up the miles for all flights you take in a year within each group.
How the estimate is calculated
Each activity is multiplied by an emission factor — the amount of carbon dioxide (or CO₂ equivalent) released per unit. The factors below come from the U.S. EPA. All results are approximate.
| Activity | Factor used |
|---|---|
| Gasoline | 8.887 kg CO₂ per gallon |
| Diesel | 10.18 kg CO₂ per gallon |
| Natural gas | 5.31 kg per therm · 5.44 per CCF · 54.4 per MCF |
| Heating oil (distillate No. 2) | 10.21 kg CO₂ per gallon |
| Electricity | ≈0.35 kg CO₂e per kWh (U.S. average, editable) |
| Short flight (<300 mi) | ≈0.209 kg CO₂e per passenger-mile |
| Medium flight (300–2,300 mi) | ≈0.130 kg CO₂e per passenger-mile |
| Long flight (2,300+ mi) | ≈0.162 kg CO₂e per passenger-mile |
Notes on accuracy
- Electricity varies the most. Depending on your local grid, the factor can range from roughly 0.2 to more than 0.6 kg per kWh. Choose the closest option above, or enter your utility's own figure.
- Flight factors are averages across aircraft and seating. The EPA figures used here don't clearly include the extra warming effect of contrails at altitude, so real climate impact may be higher.
- Gasoline and diesel factors count CO₂ only — the small methane and nitrous oxide emissions from tailpipes are left out.
Sources
Frequently asked questions
Why does the result leave out food and shopping?
Those emissions can't be measured from a bill or an odometer, and estimates for them vary widely by source. Keeping to energy and travel means every number here traces to a published emission factor.
Is CO₂ the same as CO₂e?
CO₂e ("carbon dioxide equivalent") bundles other greenhouse gases like methane into a single number using their warming strength. Fuel factors here are mostly CO₂; the electricity and flight factors are CO₂e.
How can I find my grid's emission factor?
The EPA's eGRID publishes emission rates by region. Some utilities also list their own rate on their website or bill.
What's the fastest way to lower my number?
Look at your biggest category first. For many households that's driving or home heating; for frequent flyers it's often flights. The results below show your largest source and what a 10% cut would save.
Your inputs stay in your browser — nothing is uploaded or stored.