Carbon Footprint Calculator
Enter a year of electricity, heating fuel, driving and flights, and this carbon footprint calculator multiplies each by EPA's emission factor and adds them up in metric tons of CO2-equivalent.
Notice: For general informational purposes only. Figures are estimates based on the EPA's published emission factors and are not suitable for regulatory reporting, financial disclosure or environmental marketing claims.
Carbon footprint
- Total a year 10,647 kg, or 23,472 lb, of carbon dioxide equivalent: CO2 plus methane at 28 times and nitrous oxide at 265 times its weight.
- 10.65 t CO2e
- Electricity 33% of the total. 10,000 kWh x 0.3516 kg CO2e per kWh, the US average: 771.5 lb CO2, 0.057 lb CH4 and 0.008 lb N2O per MWh in eGRID2023.
- 3,516 kg
- Natural gas 24.9% of the total. 500 therms x 0.1 mmBtu x 53.06 kg CO2 per mmBtu, plus CH4 and N2O: 5.311 kg CO2e per therm.
- 2,656 kg
- Driving 39.6% of the total. 12,000 miles / 25.0 mpg = 480.0 gallons x 8.78 kg CO2 per gallon of gasoline.
- 4,214 kg
- Flights 2.4% of the total. Short 0 kg, medium 260 kg, long 0 kg, at EPA's per passenger-mile factors.
- 260 kg
| Region | kg CO2e per kWh | Your electricity, kg CO2e |
|---|---|---|
| US average | 0.3516 | 3,516 |
| ASCC Alaska Grid (AKGD) | 0.4103 | 4,103 |
| ASCC Miscellaneous (AKMS) | 0.2364 | 2,364 |
| WECC Southwest (AZNM) | 0.3373 | 3,373 |
| WECC California (CAMX) | 0.1988 | 1,988 |
| ERCOT All (ERCT) | 0.3360 | 3,360 |
| FRCC All (FRCC) | 0.3649 | 3,649 |
| HICC Miscellaneous (HIMS) | 0.5135 | 5,135 |
| HICC Oahu (HIOA) | 0.6798 | 6,798 |
| MRO East (MROE) | 0.6395 | 6,395 |
| MRO West (MROW) | 0.4202 | 4,202 |
| NPCC New England (NEWE) | 0.2454 | 2,454 |
| WECC Northwest (NWPP) | 0.2882 | 2,882 |
| NPCC NYC/Westchester (NYCW) | 0.4428 | 4,428 |
| NPCC Long Island (NYLI) | 0.5395 | 5,395 |
| NPCC Upstate NY (NYUP) | 0.1096 | 1,096 |
| Puerto Rico Miscellaneous (PRMS) | 0.7023 | 7,023 |
| RFC East (RFCE) | 0.2708 | 2,708 |
| RFC Michigan (RFCM) | 0.4388 | 4,388 |
| RFC West (RFCW) | 0.4155 | 4,155 |
| WECC Rockies (RMPA) | 0.4726 | 4,726 |
| SPP North (SPNO) | 0.3935 | 3,935 |
| SPP South (SPSO) | 0.4059 | 4,059 |
| SERC Mississippi Valley (SRMV) | 0.3363 | 3,363 |
| SERC Midwest (SRMW) | 0.5656 | 5,656 |
| SERC South (SRSO) | 0.3831 | 3,831 |
| SERC Tennessee Valley (SRTV) | 0.4086 | 4,086 |
| SERC Virginia/Carolina (SRVC) | 0.2690 | 2,690 |
- Combustion only, as EPA's factors are: the emissions from burning the fuel or generating the electricity, not from producing and delivering the fuel. Food, goods and services are not counted.
- Driving counts CO2 only. EPA gives the small CH4 and N2O amounts for cars per mile by model year, which this calculator does not ask for.
How the Carbon Footprint Calculator works
A carbon footprint is activity times an emission factor, added up. This carbon footprint calculator uses EPA's 2025 GHG Emission Factors Hub for every factor: kilograms of carbon dioxide, and grams of methane and nitrous oxide, per kWh, therm, gallon or passenger-mile. Methane counts 28 times and nitrous oxide 265 times their weight in CO2-equivalent, the 100-year warming potentials EPA uses.
Electricity depends on where you live, because the grid mix does. EPA's eGRID2023 rates run from 241.0 lb of CO2 per MWh in upstate New York to 1,543.0 in Puerto Rico, with a US average of 771.5. With methane and nitrous oxide that average is 0.3516 kg CO2e per kWh. In the California region it is 0.1988 and in the SERC Midwest region 0.5656, so the same 10,000 kWh is 1,988 kg in one and 5,656 kg in the other. The table shows your electricity in every region.
Heating fuels use one national factor each. Natural gas is 53.06 kg of CO2 per million Btu, and a therm is 0.1 million Btu, so with methane and nitrous oxide a therm is 5.311 kg CO2e. A gallon of heating oil is 10.243 kg and a gallon of propane 5.741 kg.
Driving is gallons burned times 8.78 kg of CO2 a gallon for gasoline, or 10.21 for diesel. Flights are per passenger-mile, by trip length: 0.209 kg CO2e on flights under 300 miles, 0.130 from 300 to 2,300 miles and 0.164 beyond.
The default example is a household using 10,000 kWh on the US average grid and 500 therms of gas, driving 12,000 miles at 25 mpg and flying 2,000 miles in medium-length flights. That is 3,516 kg from electricity, 2,656 kg from gas, 4,214 kg from driving and 260 kg from flights: 10.65 t of CO2e a year.
Combustion only, as EPA's factors are: the emissions from burning the fuel or generating the electricity, not from producing and delivering the fuel. Food, goods and services are not counted. Driving counts CO2 only. EPA gives the small CH4 and N2O amounts for cars per mile by model year, which this calculator does not ask for. As a footprint calculator it measures the energy a household buys and burns directly, which is the part bills record.
Carbon Footprint Calculator FAQ
How do I calculate my carbon footprint?
Multiply each activity by its emission factor and add them up: kWh by your grid region's factor, therms of gas by 5.311 kg, gallons of gasoline by 8.78 kg, and flight miles by EPA's per passenger-mile factor. The example household comes to 10.65 t of CO2e a year.
How much CO2 does 1 kWh of electricity produce?
On EPA's eGRID2023 US average, 771.5 lb of CO2 per MWh, or 0.3499 kg per kWh, and 0.3516 kg CO2e with methane and nitrous oxide. It ranges from 0.1096 kg in upstate New York to 0.7023 kg in Puerto Rico.
How much CO2 does a gallon of gasoline produce?
8.78 kg of CO2, about 19.4 lb, from EPA's factor for motor gasoline. A gallon of diesel produces 10.21 kg.
What is the carbon footprint of a flight?
EPA's factors are per passenger-mile: 0.130 kg CO2e for flights of 300 to 2,300 miles, so a 1,000 mile flight is about 130 kg per passenger. The air miles calculator gives the distance between two airports.